Golf balls incorporating thermoplastic blend(s) of ionomer(s), thermoplastic polymer(s), and abs and/or asa

ABSTRACT

Golf ball incorporating thermoplastic blend of (i) ionomer(s); (ii) different thermoplastic polymer(s) selected from thermoplastic polyurethane(s), thermoplastic urea(s), and/or thermoplastic urea-urethane hybrid(s); and (iii) acrylonitrile styrene acrylate(s) and/or acrylonitrile butadiene styrene(s) (“ASA and/or ABS”). Ionomer(s) present in amount of about 45 wt % or greater and ASA and/or ABS present in amount of from about 2 wt % to about 35 wt %. Thermoplastic polymer(s) may be present in amounts about 8 wt % to about 50 wt %; or about 25 wt % to about 45 wt %; or about 35 wt % to about 50 wt %. Ionomer amount may be greater than thermoplastic polymer amount. Thermoplastic polymer may be a polyurethane present in amount of greater than 20 wt % to about 40 wt %; while ASA and/or ABS is present in amount of from about 5 wt % to about 30 wt %. ASA and/or ABS sometimes present in amount of from about 15 wt % to about 35 wt %.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of both of co-pending U.S.patent application Ser. No. 16/186,806, filed on Nov. 12, 2018 (the“'806 application”) and co-pending U.S. patent application Ser. No.16/186,856, filed on Nov. 12, 2018 (the “'856 application”). The '856application is a continuation of the '806 application, which is acontinuation-in-part of both of co-pending U.S. patent application Ser.No. 15/813,463, filed on Nov. 15, 2017 (the “'463 application”) andco-pending U.S. patent application Ser. No. 15/813,486, filed on Nov.15, 2017 (the “'486 application”). The '486 application is acontinuation of the '463 application. Each of these applications ishereby incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

Golf balls incorporating durable thermoplastic polyurethane compositionsand methods of making same.

BACKGROUND OF THE INVENTION

Both professional and amateur golfers use multi-piece, solid golf ballstoday. Basically, a two-piece solid golf ball includes a solid innercore protected by an outer cover. The inner core is made of a natural orsynthetic rubber such as polybutadiene, styrene butadiene, orpolyisoprene. The cover surrounds the inner core and may be made of avariety of materials including ethylene acid copolymer ionomers,polyamides, polyesters, polyurethanes, and polyureas.

Three-piece, four-piece, and even five-piece balls have become morepopular over the years. More golfers are playing with these multi-pieceballs for several reasons including new manufacturing technologies,lower material costs, and desirable ball playing performance properties.Many golf balls used today have multi-layered cores comprising an innercore and at least one surrounding outer core layer. For example, theinner core may be made of a relatively soft and resilient material,while the outer core may be made of a harder and more rigid material.The “dual-core” sub-assembly is encapsulated by a single ormulti-layered cover to provide a final ball assembly. Differentmaterials are used in these golf ball constructions to impart specificproperties and playing features to the ball.

For instance, in recent years, there has been high interest in usingpolyurethane compositions to make golf ball covers. Generally,polyurethane compositions contain urethane linkages formed by reactingan isocyanate group (—N═C═O) with a hydroxyl group (OH). Polyurethanesare produced by the reaction of a multi-functional isocyanate with apolyol in the presence of a catalyst and other additives. The chainlength of the polyurethane prepolymer is extended by reacting it withhydroxyl-terminated and amine curing agents.

In Sullivan et al., U.S. Pat. No. 5,971,870, thermoplastic orthermosetting polyurethanes and ionomers are described as being suitablematerials for making outer cover and any inner cover layer. The coverlayers can be formed over the cores by injection-molding, compressionmolding, casting or other conventional molding techniques. Preferably,each cover layer is separately formed. In one embodiment, the innercover layer is first injection molded over the core in a cavity mold,subsequently any intermediate cover layers are injection molded over theinner cover layer in a cavity mold, and finally the outer cover layer isinjection molded over the intermediate cover layers in a dimpled cavitymold.

In Sullivan et al., U.S. Pat. No. 7,131,915, the outer cover can be madefrom a polyurethane composition and various aliphatic and aromaticdiisocyanates are described as being suitable for making thepolyurethanes. Depending on the type of curing agent used, thepolyurethane composition may be thermoplastic or thermoset in nature.Sullivan '915 further discloses that compositions for the intermediatecover layer and inner cover layer may be selected from the same class ofmaterials as used for the outer cover layer. In other embodiments,ionomers such as HNPs, can be used to form the intermediate and innercover layers. The castable, reactive liquid used to form the urethaneelastomer material can be applied over the core using a variety oftechniques such as spraying, dipping, spin coating, or flow coatingmethods.

As discussed above, both thermoplastic and thermosetting polyurethanescan be used to form golf ball covers. Thermoplastic polyurethanes haveminimal cross-linking; any bonding in the polymer network is primarilythrough hydrogen bonding or other physical mechanism. Because of theirlower level of cross-linking, thermoplastic polyurethanes are relativelyflexible. The cross-linking bonds in thermoplastic polyurethanes can bereversibly broken by increasing temperature such as during molding orextrusion. That is, the thermoplastic material softens when exposed toheat and returns to its original condition when cooled. On the otherhand, thermoset polyurethanes become irreversibly set when they arecured. The cross-linking bonds are irreversibly set and are not brokenwhen exposed to heat. Thus, thermoset polyurethanes typically have ahigh level of cross-linking and are relatively rigid.

One advantage with using thermoplastic polyurethane, urea and/or hybrid(TPU) compositions to form golf ball covers is that they have goodprocessability. The resulting thermoplastic materials generally havegood melt-flow properties and different molding methods may be used toform the covers. Accordingly, thermoplastic polyurethanes, urea and/orhybrid have been used for years, especially in golf ball covers.

Unfortunately, there are known drawbacks associated with using TPUmaterials, such as being less durable and less tough than otherpolymers. In this regard, a resulting thermoplastic polyurethane golfball cover may not have high mechanical strength, impact durability, andcut and scuff (groove shear)-resistance.

Thus, manufacturers have tried treating thermoplastic polyurethanes inorder to enhance the durability and strength of the polymer. Forexample, an isocyanate may be compounded into a masterbatch and then themasterbatch may be added to the thermoplastic polyurethane compositionprior to molding. In another example, the molded thermoplasticpolyurethane cover may be dipped into an isocyanate solution. Treatingthe thermoplastic polyurethane material with isocyanates helps improvethe physical properties such as mechanical strength, impact durability,and cut and scuff (groove shear)-resistance of the material. In somecases, the physical properties may not only increase, but they mayactually increase beyond the values of the non-refined material.

For example, Kennedy, III, U.S. Pat. No. 8,920,264 and Matroni, U.S.Pat. No. 9,119,990 disclose isocyanate dipping methods, whereby a golfball having a thermoplastic polyurethane cover is treated with asolution of isocyanate. The isocyanate solution can contain a solvent,for example, acetone or methyl ethyl ketone (MEK), at least oneisocyanate compound, and a catalyst. The ball is soaked in theisocyanate solution and this causes the isocyanate compound to permeatethe cover. The isocyanate compound cross-links the thermoplasticpolyurethane cover material, and this improves the physical propertiesof the cover such as durability and scuff-resistance.

Manufacturers have also tried treating and/or coating layers about a TPUcover layer in order to improve golf ball properties. In one approach,differing relative proportions of isocyanate functional groups in eachof the TPU cover layer and the coating layer enabled the coating layerto react with the TPU cover layer.

However, such approaches require additional processing steps which canbe time-consuming and therefore reduce efficiency as well as increasemanufacturing costs. Related and allowed U.S. application Ser. No.15/813,463 (“'463 application) and U.S. application Ser. No. 15/813,486(“'486 application) address these problems and provide novel solutionswherein at least one layer is comprised of a mixture consisting of (i)thermoplastic polymer (thermoplastic polyurethane(s), urea(s) and/orpolyurethane-urea hybrid(s)) (“TPU”) and (ii) polymethylmethacrylate-based copolymer(s) or a plurality of a plurality ofcore-shell polymers wherein the core and/or shell contains polymethylmethacrylate-based copolymer(s). The resulting materials and golf ballsare reliably durable and possess good physical and playing performanceproperties and yet can be produced more simply and cost effectivelywithout the need for additional treatments and/or coating layers.

Subsequently, related U.S. application Ser. No. 16/186,806 (“'806application”) and U.S. application Ser. No. 16/186,856(“'856application”) introduced thermoplastic blends which incorporate some ofthe teachings and benefits of the materials of parent applications '463and '486 to create novel golf balls and layers which possess and producethe desired physical and playing performance properties of ionomer(s),TPU(s) and polymethyl (meth)acrylate-based copolymer(s) and/or aplurality of core-shell polymers having a core and/or a shell comprisingsame in a single layer, without encountering the problems previouslyassociated with making and using conventional TPU(s). Such golf ballsand layers are reliably durable, and can be produced simply andcost-effectively within existing golf ball manufacturing processes.Prior attempts to create ionomer(s)/TPU(s) blends such as in U.S. Pat.No. 7,700,689 of Egashira et al.; and/or U.S. Publ. No. 2011/0224023 ofTutmark; and/or U.S. Publ. No. 2018/0147452 of Song et al. had notaddressed nor resolved these issues.

However, there still remains a need to develop differentionomer(s)/TPU(s) blends based on some of the teachings of the materialsof parents '463 and '486 applications and combine multiple uniquedesired chemical, physical and playing performance properties in asingle layer without meanwhile encountering the problems previouslyassociated with making and using conventional TPU(s).

Such novel golf balls and ionomer(s)/TPU(s) blends, if meanwhile capableof being manufactured cost effectively within existing manufacturingprocesses, would be particularly useful. Golf balls of the presentinvention and methods for making same address and solve this need.

SUMMARY OF THE INVENTION

A golf ball of the invention may comprise a core and at least one layercomprising a thermoplastic blend of (i) at least one ionomer; (ii) atleast one thermoplastic polyurethane; and (iii) at least oneacrylonitrile styrene acrylate, acrylonitrile butadiene styrene, orcombinations thereof (“ASA and/or ABS”); wherein the ionomer is presentin an amount of about 45 wt % or greater and the ASA and/or ABS ispresent in an amount of from about 2 wt % to about 35 wt %. Thethermoplastic polyurethane may be present in the blend in an amount offrom about 8 wt % to about 50 wt %. In another embodiment, thethermoplastic polyurethane may be present in an amount of from about 25wt % to about 45 wt %. In yet another embodiment, the thermoplasticpolyurethane may be present in an amount of from about 35 wt % to about50 wt %.

In a specific embodiment, the ionomer is present in the blend in anamount greater than the amount of thermoplastic polyurethane. In oneembodiment, the ionomer is present in an amount of from about 45 wt % toabout 70 wt %.

In one embodiment, the thermoplastic polyurethane may be present in anamount greater than 20 wt % and up to about 40 wt %; and the ASA and/orABS is present in an amount of from about 5 wt % to about 30 wt %. Insome embodiments, the ASA and/or ABS is present in an amount of fromabout 15 wt % to about 35 wt %.

A golf ball of the invention may comprise at least one layer comprisinga three-part thermoplastic blend consisting of: (i) at least oneionomer; (ii) at least one different thermoplastic polymer consisting ofat least one thermoplastic polyurethane, thermoplastic urea,thermoplastic urea-urethane hybrid, or a combination thereof; and (iii)at least one acrylonitrile styrene acrylate, acrylonitrile butadienestyrene, or combinations thereof (“ASA and/or ABS”). The three-partthermoplastic blend includes (i), (ii), and (iii) in a wt % ratio I:T:C;wherein I is the wt % of ionomer, T is the wt % of differentthermoplastic polymer, and C is the wt % of ASA and/or ABS; and whereinI is >45 and 2≤C<35.

In one embodiment, T is 25 to 50. In another embodiment, T is about25-50. In yet another embodiment, T is greater than 25 and up to 50. Instill another embodiment, T is 30-50. In one embodiment, T is 35 to 60.In an alternative embodiment, T is 45 to 60. T may also be greater than45 and up to about 60.

In a different embodiment, T is from about 8 to 45.

In one embodiment, I>T. In another embodiment, T>I. In yet another suchembodiment, T=I.

In a particular embodiment, 45<I<70.

In a different embodiment, I is 48-90.

In one such specific embodiment, T is greater than 20 and up to about40; and C is 3-30. In one particular embodiment, 15≤C<35. In anotherparticular embodiment, 20≤C<35. The ASA may be comprised of at least 60%acrylate and/or the ABS may be comprised of at least 60% butadiene.

In one embodiment, the three-part thermoplastic blend has a materialhardness of from about 20 Shore D to about 65 Shore D.

The three-part thermoplastic blend may have a material hardness that isdifferent than the material hardness of the thermoplastic polymer.

In one embodiment, the three-part thermoplastic blend has a materialhardness greater than about 20 Shore D and up to about 70 Shore D.

In one embodiment, the at least one layer is a cover layer thatsurrounds a subassembly and has a hardness H that differs from ahardness H_((ii)) of (ii) by at least about 5 Shore D hardness points;wherein (ii) has a hardness of from about 20 Shore D to about 70 ShoreD.

In another embodiment, the at least one layer is an inner cover layerthat surrounds a subassembly and is surrounded by an outer cover layerand has a hardness H that differs from a hardness H_((ii)) of (ii) by atleast about 5 Shore D hardness points; wherein (ii) has a hardness offrom about 20 Shore D to about 70 Shore D.

In some embodiments, a golf ball of the invention comprises at least onelayer consisting of a three-part thermoplastic blend consisting of: (i)at least one ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or combination thereof; and(iii) ASA and/or ABS.

The invention also relates to a method of making a golf ball of theinvention, comprising: providing a subassembly; and forming at least onelayer about the subassembly consisting of a three-part thermoplasticblend consisting of: (i) at least one ionomer; (ii) at least onedifferent thermoplastic polymer consisting of at least one thermoplasticpolyurethane, thermoplastic urea, thermoplastic urea-urethane hybrid, ora combination thereof; and (iii) ASA and/or ABS. The three-partthermoplastic blend includes (i), (ii), and (iii) in a wt % ratio I:T:C;wherein I is the wt % of ionomer, T is the wt % of differentthermoplastic polymer, and C is the wt % of ASA and/or ABS; and whereinI is >45 and 2≤C<35.

In another embodiment, the method of making a golf ball of theinvention, comprises: providing a subassembly; and forming at least onelayer about the subassembly comprising a three-part thermoplastic blendconsisting of: (i) at least one ionomer; (ii) at least one differentthermoplastic polymer consisting of at least one thermoplasticpolyurethane, thermoplastic urea, thermoplastic urea-urethane hybrid, ora combination thereof; and (iii) ASA and/or ABS.

In other embodiments, the method comprises providing a subassemblyconsisting of a three-part thermoplastic blend consisting of: (i) atleast one ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or a combination thereof; and(iii) ASA and/or ABS; and forming at least one layer comprising athermoset or thermoplastic composition about the subassembly.

Alternatively, the method may comprise providing a subassemblycomprising a three-part thermoplastic blend consisting of: (i) at leastone ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or a combination thereof; and(iii) ASA and/or ABS; and forming at least one layer comprising athermoset or thermoplastic composition about the subassembly.

DETAILED DESCRIPTION OF THE INVENTION

Advantageously, golf balls of the invention incorporate in at least onelayer, such as a cover, novel thermoplastic blend(s) of ionomer(s),TPU(s), and ASA and/or ABS (acrylonitrile styrene acrylate(s),acrylonitrile butadiene styrene(s), or combinations thereof). Thethermoplastic blends of the invention are desirably durable and tough,having high mechanical strength, impact durability, and cut and scuff(groove shear)-resistance, providing in a single layer the uniqueproperties of each part of the blend without meanwhile sacrificing thegood processability typically associated with producing thermoplasticmaterials.

Advantageously, golf balls of the invention include ionomers and TPUsand their respective benefits in a single layer without meanwhilesacrificing processability (e.g., possesses good melt-flow properties)or durability and toughness. The thermoplastic blend can be moldedcost-effectively using a wide range of methods, yet displays highmechanical strength, impact durability, and cut and scuff (grooveshear)-resistance.

A golf ball of the invention may comprise a core and at least one layercomprising a thermoplastic blend of (i) at least one ionomer; (ii) atleast one thermoplastic polyurethane; and (iii) at least oneacrylonitrile styrene acrylate, acrylonitrile butadiene styrene, orcombinations thereof (“ASA and/or ABS”); wherein the ionomer is presentin an amount of about 45 wt % or greater and the ASA and/or ABS ispresent in an amount of from about 2 wt % to about 35 wt %.

The thermoplastic polyurethane may be present in the blend in an amountof from about 8 wt % to about 50 wt %. In another embodiment, thethermoplastic polyurethane may be present in an amount of from about 25wt % to about 45 wt %. In yet another embodiment, the thermoplasticpolyurethane may be present in an amount of from about 35 wt % to about50 wt %.

In a specific embodiment, the ionomer is present in the blend in anamount greater than the amount of thermoplastic polyurethane. In oneembodiment, the ionomer is present in an amount of from about 45 wt % toabout 70 wt %.

In one embodiment, the thermoplastic polyurethane may be present in anamount greater than 20 wt % and up to about 40 wt %; and the ASA and/orABS is present in an amount of from about 5 wt % to about 30 wt %. Insome embodiments, the ASA and/or ABS is present in an amount of fromabout 15 wt % to about 35 wt %.

A golf ball of the invention may comprise at least one layer comprisinga three-part thermoplastic blend consisting of: (i) at least oneionomer; (ii) at least one different thermoplastic polymer consisting ofat least one thermoplastic polyurethane, thermoplastic urea,thermoplastic urea-urethane hybrid, or combination thereof; and (iii)ASA and/or ABS. The three-part thermoplastic blend includes (i), (ii),and (iii) in a wt % ratio I:T:C; wherein I is the wt % of ionomer, T isthe wt % of different thermoplastic polymer, and C is the wt % of ASAand/or ABS; and wherein I is >45 and 2≤C<35.

In one embodiment, T is greater than 20 and up to about 50. In anotherembodiment, T is 25-50. In yet another embodiment, T is about 25-50. Instill another embodiment, T is greater than about 25 to 50. In analternative embodiment, T is 30 to about 50, or greater than about 30 toabout 50, or greater than 30 to 60. In a particular embodiment, T is35-60, or about 35-60, or about 35-50, or greater than 35 to about 50,or about 40-50. In one embodiment, T is greater than 40 and up to about50. In other embodiments, T is 40-50.

There are different embodiments wherein 8<T<50, or T is from about 8 to40.

In one embodiment, I>T. In an alternative embodiments, T>I. In anotherembodiment, T=I.

In a specific embodiment, I<90. In a particular embodiment, 45<I<70. Ina different embodiment, I is 48-90.

In one such specific embodiment, T is greater than 20 and up to about40; and C is 3-30.

In one particular embodiment, 15≤C<35. In another particular embodiment,20≤C<35.

The ASA may be comprised of at least 60% acrylate and/or the ABS may becomprised of at least 60% butadiene.

In one embodiment, the three-part thermoplastic blend has a materialhardness of from about 20 Shore D to about 65 Shore D.

The three-part thermoplastic blend may have a material hardness that isdifferent than the material hardness of the thermoplastic polymer.

In one embodiment, the three-part thermoplastic blend has a materialhardness greater than about 20 Shore D and up to about 70 Shore D.

In one embodiment, the at least one layer is a cover layer thatsurrounds a subassembly and has a hardness H that differs from ahardness H_((ii)) of (ii) by at least about 5 Shore D hardness points;wherein (ii) has a hardness of from about 20 Shore D to about 70 ShoreD.

In another embodiment, the at least one layer is an inner cover layerthat surrounds a subassembly and is surrounded by an outer cover layerand has a hardness H that differs from a hardness H_((ii)) of (ii) by atleast about 5 Shore D hardness points; wherein (ii) has a hardness offrom about 20 Shore D to about 70 Shore D.

In some embodiments, a golf ball of the invention comprises at least onelayer consisting of a three-part thermoplastic blend consisting of: (i)at least one ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or combination thereof; and(iii) ASA and/or ABS.

In particular embodiments, 20<T<50, or 20≤T≤50, or 20<T≤50, or 20<T<40,or 20≤T≤40, or 25≤T<50, or 25<T≤50, or 25≤T<40, or 30≤T<50, or 30≤T<40,or 40≤T≤50, or 40<T<50, or 15≤T<50, or 15≤T<30.

In different embodiments, T is 8≤T≤50, or 8≤T<50, or 8<T≤50, or 8<T<50,or 8-45, or about 8-45, or 8≤T≤40, or 8≤T<40, or 8<T≤40, or 8≤T≤40, or8≤T≤30, or 8≤T<30, or 8<T≤30, or 8<T<30, or 8≤T≤20, or 8≤T<20, or8<T≤20, or 8<T<20, or 8≤T≤15, or 8≤T<15, or 8<T≤15, or 8<T<15.

In specific formulations, 5≤C<35, or 10≤C<35, or 15≤C<35, or 15≤C≤35, or15≤C<25, or 15≤C≤25, or 20≤C<35, or 20≤C≤35, or 20≤C<25, or 15≤C≤20.

In particular embodiments, 45<I<70, or 45<I≤70, or 45<I≤60, or 45<I<60,or 55≤I<70, or 55≤I≤70.

Since I is always greater than 45, and 2≤C<35, T will always be at mostabout 50. This being said, many possible combinations of I, T and C maytherefore be targeted and coordinated within the ranges disclosedherein. In one specific such example, I>45, C<35, and T>20. In anothersuch specific embodiment, I>45, C<30, and T>25. In yet another suchembodiment, I>45, C<20, and T>35. In still another such embodiment,I>45, C<15, and T>40. In a different embodiment, I>45, C≥2, and T≤53.

In one specific non-limiting example, I is 90, T is 8, and C is 2. Inanother specific non-limiting example, I is 80, T is 15, and C is 5. Inyet another specific non-limiting example, I is 70, T is 20 and C is 10.In still another specific non-limiting example, I is 60, T is 25 and Cis 15. In an alternative specific non-limiting example, I is 50, T is 30and C is 20. In a different specific non-limiting example, I is 50, T is20 and C is 30. In a different specific non-limiting example, I is 46, Tis 50 and C is 4. In another specific non-limiting example, I is 45, Tis 45 and C is 10. In yet another specific non-limiting example, I is47, T is 43 and C is 10.

In some embodiments, a golf ball of the invention comprises at least onelayer consisting of a three-part thermoplastic blend consisting of: (i)at least one ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or combination thereof; and(iii) ASA and/or ABS. Once again, the three-part thermoplastic blendincludes (i), (ii), and (iii) in a wt % ratio I:T:C; wherein I is the wt% of ionomer, T is the wt % of different thermoplastic polymer, and C isthe wt % of ASA and/or ABS; and wherein I is >45 and 2≤C<35.

As used herein the term “thermoplastic polymer” refers to athermoplastic composition including one or more thermoplastic polymersother than ionomer(s) as defined herein. In one such embodiment, thethermoplastic polymer may comprise a thermoplastic polyurethane, athermoplastic urea, a thermoplastic urea-urethane hybrid, orcombination(s) thereof. The thermoplastic polyurethane itself mayinclude blends of thermoplastic urethanes/polyurethanes. Thethermoplastic urea itself may include blends of thermoplasticureas/polyureas. And the urea-urethane hybrid itself may includemultiple differing hybrids.

The thermoplastic polymer of the three-part thermoplastic blend mayadditionally include/contain additional materials/ingredients such asfillers, additives, catalysts, wetting agents, coloring agents, opticalbrighteners, cross-linking agents, whitening agents such as titaniumdioxide and zinc oxide, ultraviolet (UV) light absorbers, hindered aminelight stabilizers, defoaming agents, processing aids, surfactants, andother conventional additives such as antioxidants, stabilizers,softening agents, plasticizers, impact modifiers, foaming agents,density-adjusting fillers, reinforcing materials, compatibilizers, andthe like.

Interactions between each of the ionomer, the thermoplastic polymer, andASA and/or ABS create a resulting thermoplastic material having superiormechanical strength, impact durability, and cut and scuff (grooveshear)-resistance compared to the thermoplastic polymer alone and canbetter and more reliably sustain the great force and impact of a clubface sticking the golf ball on the course.

The resulting three-part thermoplastic blend of the invention also mayhave a greater flexural modulus (ASTM D-790), tensile strength (ASTMD-638), and ultimate elongation (ASTM D-638) than the thermoplasticpolymer of the three-part thermoplastic blend. The relative amounts ofionomer, thermoplastic polymer, and ASA and/or ABS can be changed,coordinated and targeted to achieve desired Tg, flexural modulus,tensile strength and/or ultimate elongation of the layer of three-partthermoplastic blend.

In one embodiment, the thermoplastic polymer may have a materialhardness of from about 20 Shore D to about 66 Shore D, or from 20 ShoreD to about 60 Shore D, or from 20 Shore D to about 50 Shore D, or from20 Shore D to about 40 Shore D, or from 20 Shore D to about 30 Shore D,or from 30 Shore D to about 66 Shore D, or from 30 Shore D to about 60Shore D, or from 30 Shore D to about 50 Shore D, or from 30 Shore D toabout 40 Shore D, or from 40 Shore D to about 66 Shore D, or from 40Shore D to about 60 Shore D, or from 40 Shore D to about 50 Shore D, orfrom 50 Shore D to about 66 Shore D, or from 50 Shore D to about 60Shore D.

In one embodiment, the three-part thermoplastic blend has a materialhardness greater than about 20 Shore D and up to about 70 Shore D, orgreater than about 30 Shore D and up to about 70 Shore D, or greaterthan about 40 Shore D and up to about 70 Shore D, or greater than about50 Shore D and up to about 70 Shore D, or greater than about 60 Shore Dand up to about 70 Shore D, or from about 25 Shore D to about Shore 70D, or from about 25 Shore D to about 60 Shore D, or from about 25 ShoreD to about 50 Shore D, or from about 25 Shore D to about 40 Shore D, orfrom about 35 Shore D to about 70 Shore D, or from about 45 Shore D toabout 60 Shore D, or from about 50 Shore D to about 70 Shore D, or fromabout 50 Shore D to about 60 Shore D.

The three-part thermoplastic blend may have a modulus that is greaterthan a modulus of the thermoplastic polymer. Thus, in such embodiments,it is envisioned that a layer of inventive three-part thermoplasticblend may have any known suitable modulus greater than the modulus ofthe thermoplastic polymer and predetermined by pre-selecting therelative amounts of ionomer, thermoplastic polymer, and component (iii)in order to target a wide range of playing characteristics.

In order to produce a three-part thermoplastic blend possessing anproducing unique and desirable golf ball properties without exhibitingthe aforementioned problems encountered with conventional TPU-containingmaterials relating to durability, toughness, mechanical strength, cutand scuff resistance, the ionomer should be included in the three-partthermoplastic blend in an amount greater than 45 wt. % of the totalweight of the blend. Meanwhile, the relative required amounts ofcomponents (ii) and (iii) of the three-part thermoplastic blend can becoordinated with each other as well as with respect to the pre-selectedrequired amount of ionomer within the range of greater than 45 wt. % ofthe total weight of the blend. Thus, as long as the required amount ofionomer is greater than 45 wt. %, components (ii) (TPU) and (iii) of thethree-part thermoplastic blend may be selected within the range of from2 wt. % to less than 35 wt. %, and greater than 20 up to 50 wt. %,respectively, based on the total weight of the three-part thermoplasticblend.

There are specific embodiments wherein the required amount of ionomerincluded in the three-part thermoplastic blend may be greater than about45 wt. % of the total weight of the blend while the required amount ofcomponent (iii) is up to about 35 wt. %, with the amount of component(ii) (TPU) being included within the range of from greater than 20 wt. %to up to about 50 wt. %.

A layer such as a cover containing the three-part thermoplastic blendmay have a thickness of from about 0.010 inches to about 0.050 inches,or from about 0.010 inches to about 0.040 inches, or from about 0.010inches to about 0.030 inches, or from about 0.010 inches to about 0.020inches, or from about 0.015 inches to about 0.045 inches, or from about0.025 inches to about 0.045 inches, or from about 0.035 inches to about0.050 inches, or from about 0.020 inches to about 0.050 inches. It isalso envisioned that coating layers and films of three-partthermoplastic blend may be formed about a subassembly in a golf ball ofthe invention in any known thickness thereof.

The invention also relates to a method of making a golf ball of theinvention, comprising: providing a subassembly; and forming at least onelayer about the subassembly consisting of a three-part thermoplasticblend consisting of: (i) at least one ionomer; (ii) at least onedifferent thermoplastic polymer consisting of at least one thermoplasticpolyurethane, thermoplastic urea, thermoplastic urea-urethane hybrid, ora combination thereof; and (iii) ASA and/or ABS. The three-partthermoplastic blend includes (i), (ii), and (iii) in a wt % ratio I:T:C;wherein I is the wt % of ionomer, T is the wt % of differentthermoplastic polymer, and C is the wt % of ASA and/or ABS; and whereinI is >45 and 2≤C<35.

In another embodiment, the method of making a golf ball of theinvention, comprises: providing a subassembly; and forming at least onelayer about the subassembly comprising a three-part thermoplastic blendconsisting of: (i) at least one ionomer; (ii) at least one differentthermoplastic polymer consisting of at least one thermoplasticpolyurethane, thermoplastic urea, thermoplastic urea-urethane hybrid, ora combination thereof; and (iii) ASA and/or ABS.

In other embodiments, the method comprises providing a subassemblyconsisting of a three-part thermoplastic blend consisting of: (i) atleast one ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or a combination thereof; and(iii) ASA and/or ABS; and forming at least one layer comprising athermoset or thermoplastic composition about the subassembly.

Alternatively, the method may comprise providing a subassemblycomprising a three-part thermoplastic blend consisting of: (i) at leastone ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or a combination thereof; and(iii) ASA and/or ABS; and forming at least one layer comprising athermoset or thermoplastic composition about the subassembly.

The ionomer of a three-part or three-part thermoplastic blend mayinclude partially-neutralized ionomers and highly-neutralized ionomers(HNPs), including ionomers formed from blends of two or morepartially-neutralized ionomers, blends of two or more highly-neutralizedionomers, and blends of one or more partially-neutralized ionomers withone or more highly-neutralized ionomers.

lonomers, typically are ethylene/acrylic acid copolymers orethylene/acrylic acid/acrylate terpolymers in which some or all of theacid groups are neutralized with metal cations. Commercially availableionomers suitable for use with the present invention include for exampleSURLYNs® from DuPont and Ioteks® from Exxon. SURLYN® 8940 (Na), SURLYN®9650 (Zn), and SURLYN® 9910 (Zn) are examples of low acid ionomer resinswith the acid groups that have been neutralized to a certain degree witha cation. More examples of suitable low acid ionomers, e.g., Escor®4000/7030 and Escor® 900/8000, are disclosed in U.S. Pat. Nos. 4,911,451and 4,884,814, the disclosures of which are incorporated by referenceherein. High acid ionomer resins include SURLYN(® 8140 (Na) and SURLYN®8546 (Li), which have an methacrylic acid content of about 19 percent.The acid groups of these high acid ionomer resins that have beenneutralized to a certain degree with the designated cation.

Ionomers may encompass those polymers obtained by copolymerization of anacidic or basic monomer, such as alkyl (meth)acrylate, with at least oneother comonomer, such as an olefin, styrene or vinyl acetate, followedby at least partial neutralization. Alternatively, acidic or basicgroups may be incorporated into a polymer to form an ionomer by reactingthe polymer, such as polystyrene or a polystyrene copolymer including ablock copolymer of polystyrene, with a functionality reagent, such as acarboxylic acid or sulfonic acid, followed by at least partialneutralization. Suitable neutralizing sources include cations fornegatively charged acidic groups and anions for positively charged basicgroups.

For example, ionomers may be obtained by providing a cross metallic bondto polymers of monoolefin with at least one member selected from thegroup consisting of unsaturated mono- or di-carboxylic acids having 3 to12 carbon atoms and esters thereof (the polymer contains about 1 percentto about 50 percent by weight of the unsaturated mono- or di-carboxylicacid and/or ester thereof). In one embodiment, the ionomer is an E/X/Ycopolymers where E is ethylene, X is a softening comonomer, such asacrylate or methacrylate, present in 0 percent to about 50 percent byweight of the polymer (preferably 0 weight percent to about 25 weightpercent, most preferably 0 weight percent to about 20 weight percent),and Y is acrylic or methacrylic acid present in about 5 to about 35weight percent of the polymer, wherein the acid moiety is neutralizedabout 1 percent to about 100 percent (preferably at least about 40percent, most preferably at least about 60 percent) to form an ionomerby a cation such as lithium, sodium, potassium, magnesium, calcium,barium, lead, tin, zinc, or aluminum, or a combination of such cations.

Any of the acid-containing ethylene copolymers discussed above may beused to form an ionomer according to the present invention. In addition,the ionomer may be a low acid or high acid ionomer. As detailed above, ahigh acid ionomer may be a copolymer of an olefin, e.g., ethylene, andat least 16 weight percent of an α,β-ethylenically unsaturatedcarboxylic acid, e.g., acrylic or methacrylic acid, wherein about 10percent to about 100 percent of the carboxylic acid groups areneutralized with a metal ion. In contrast, a low acid ionomer containsabout 15 weight percent of the α,β-ethylenically unsaturated carboxylicacid.

Suitable commercially available ionomer resins include SURLYNs® (DuPont)and Ioteks® (Exxon). Other suitable ionomers for use in the blends ofthe present invention include polyolefins, polyesters, polystyrenes,SBS, SEBS, and polyurethanes, in the form of homopolymers, copolymers,or block copolymer ionomers.

The ionomers may also be blended with highly neutralized polymers (HNP).As used herein, a highly neutralized polymer has greater than about 70percent of the acid groups neutralized. In one embodiment, about 80percent or greater of the acid groups are neutralized. In anotherembodiment, about 90 percent or greater of the acid groups areneutralized. In still another embodiment, the HNP is a fully neutralizedpolymers, i.e., all of the acid groups (100 percent) in the polymercomposition are neutralized.

Suitable HNPs include, but are not limited to, polymers containingα,β-unsaturated carboxylic acid groups, or the salts thereof, that havebeen highly neutralized by organic fatty acids. Such HNPs arecommercially available from DuPont under the trade name HPF, e.g., HPF1000 and HPF 2000. The HNP can also be formed using an oxa-containingcompound as a reactive processing aid to avoid processing problems, asdisclosed in U.S. Patent Publication No. 2003/0225197. In particular, anHNP can include a thermoplastic resin component having an acid or ionicgroup, i.e., an acid polymer or partially neutralized polymer, combinedwith an oxa acid, an oxa salt, an oxa ester, or combination thereof andan inorganic metal compound or organic amine compound. As used herein, apartially neutralized polymer should be understood to mean polymers withabout 10 to about 70 percent of the acid groups neutralized. Forexample, the HNP can includes about 10 percent to about 30 percent byweight of at least one oxa acid, about 70 percent to about 90 percent byweight of at least one thermoplastic resin component, and about 2percent to about 6 percent by weight of an inorganic metal compound,organic amine, or a combination thereof.

In addition, the HNP can be formed from an acid copolymer that isneutralized by one or more amine-based or an ammonium-based components,or mixtures thereof, as disclosed in co-pending U.S. patent applicationSer. No. 10/875,725, filed Jun. 25, 2004, entitled “Golf BallCompositions Neutralized with Ammonium-Based and Amine-Based Compounds,”which is incorporated in its entirety by reference herein.

Furthermore, those of ordinary skill in the art will appreciate that theHNPs may be neutralized using one or more of the above methods. Forexample, an acid copolymer that is partially or highly neutralized in amanner described above may be subjected to additional neutralizationusing more traditional processes, e.g., neutralization with salts oforganic fatty acids and/or a suitable cation source.

In a particular embodiment, the core includes at least one additionalthermoplastic intermediate core layer formed from a compositioncomprising an ionomer selected from DuPont® HPF ESX 367, HPF 1000, HPF2000, HPF AD1035, HPF AD1035 Soft, HPF AD1040, and AD1172 ionomers,commercially available from E. I. du Pont de Nemours and Company. Thecoefficient of restitution (“COR”), compression, and surface hardness ofeach of these materials, as measured on 1.55″ injection molded spheresaged two weeks at 23° C./50% RH, are given in Table 1 below.

TABLE 1 Solid Sphere Solid Sphere Solid Sphere Shore D Example CORCompression Surface Hardness HPF 1000 0.830 115 54 HPF 2000 0.860 90 47HPF AD1035 0.820 63 42 HPF AD1035 Soft 0.780 33 35 HPF AD 1040 0.855 13560 HPF AD1172 0.800 32 37

In one embodiment, an intermediate layer is disposed between the singleor multi-layered core and surrounding cover layer. These intermediatelayers also can be referred to as casing or inner cover layers. Theintermediate layer can be formed from any materials known in the art,including thermoplastic and thermosetting materials, but preferably isformed of an ionomer composition comprising an ethylene acid copolymercontaining acid groups that are at least partially neutralized. Suitableethylene acid copolymers that may be used to form the intermediatelayers are generally referred to as copolymers of ethylene; C₃ to C₈α,β-ethylenically unsaturated mono- or dicarboxylic acid; and optionalsoftening monomer. These ethylene acid copolymer ionomers also can beused to form the inner core and outer core layers as described above.

Suitable ionomer compositions include partially-neutralized ionomers andhighly-neutralized ionomers (HNPs), including ionomers formed fromblends of two or more partially-neutralized ionomers, blends of two ormore highly-neutralized ionomers, and blends of one or morepartially-neutralized ionomers with one or more highly-neutralizedionomers. For purposes of the present disclosure, “HNP” refers to anacid copolymer after at least 70% of all acid groups present in thecomposition are neutralized. Preferred ionomers are salts of O/X- andO/X/Y-type acid copolymers, wherein 0 is an α-olefin, X is a C₃-C₈α,β-ethylenically unsaturated carboxylic acid, and Y is a softeningmonomer. 0 is preferably selected from ethylene and propylene. X ispreferably selected from methacrylic acid, acrylic acid, ethacrylicacid, crotonic acid, and itaconic acid. Methacrylic acid and acrylicacid are particularly preferred. Y is preferably selected from (meth)acrylate and alkyl (meth) acrylates wherein the alkyl groups have from 1to 8 carbon atoms, including, but not limited to, n-butyl (meth)acrylate, isobutyl (meth) acrylate, methyl (meth) acrylate, and ethyl(meth) acrylate.

Preferred O/X and O/X/Y-type copolymers include, without limitation,ethylene acid copolymers, such as ethylene/(meth)acrylic acid,ethylene/(meth)acrylic acid/maleic anhydride, ethylene/(meth)acrylicacid/maleic acid mono-ester, ethylene/maleic acid, ethylene/maleic acidmono-ester, ethylene/(meth)acrylic acid/n-butyl (meth)acrylate,ethylene/(meth)acrylic acid/iso-butyl (meth)acrylate,ethylene/(meth)acrylic acid/methyl (meth)acrylate,ethylene/(meth)acrylic acid/ethyl (meth)acrylate terpolymers, and thelike. The term, “copolymer,” as used herein, includes polymers havingtwo types of monomers, those having three types of monomers, and thosehaving more than three types of monomers. Preferred α, β-ethylenicallyunsaturated mono- or dicarboxylic acids are (meth) acrylic acid,ethacrylic acid, maleic acid, crotonic acid, fumaric acid, itaconicacid. (Meth) acrylic acid is most preferred. As used herein, “(meth)acrylic acid” means methacrylic acid and/or acrylic acid. Likewise,“(meth) acrylate” means methacrylate and/or acrylate.

In a particularly preferred version, highly neutralized E/X- andE/X/Y-type acid copolymers, wherein E is ethylene, X is a C₃-C₈α,β-ethylenically unsaturated carboxylic acid, and Y is a softeningmonomer are used. X is preferably selected from methacrylic acid,acrylic acid, ethacrylic acid, crotonic acid, and itaconic acid.Methacrylic acid and acrylic acid are particularly preferred. Y ispreferably an acrylate selected from alkyl acrylates and aryl acrylatesand preferably selected from (meth) acrylate and alkyl (meth) acrylateswherein the alkyl groups have from 1 to 8 carbon atoms, including, butnot limited to, n-butyl (meth) acrylate, isobutyl (meth) acrylate,methyl (meth) acrylate, and ethyl (meth) acrylate. Preferred E/X/Y-typecopolymers are those wherein X is (meth) acrylic acid and/or Y isselected from (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth)acrylate, methyl (meth) acrylate, and ethyl (meth) acrylate. Morepreferred E/X/Y-type copolymers are ethylene/(meth) acrylic acid/n-butylacrylate, ethylene/(meth) acrylic acid/methyl acrylate, andethylene/(meth) acrylic acid/ethyl acrylate.

The amount of ethylene in the acid copolymer is typically at least 15wt. %, preferably at least 25 wt. %, more preferably least 40 wt. %, andeven more preferably at least 60 wt. %, based on total weight of thecopolymer. The amount of C₃ to C₈ α, β-ethylenically unsaturated mono-or dicarboxylic acid in the acid copolymer is typically from 1 wt. % to35 wt. %, preferably from 5 wt. % to 30 wt. %, more preferably from 5wt. % to 25 wt. %, and even more preferably from 10 wt. % to 20 wt. %,based on total weight of the copolymer. The amount of optional softeningcomonomer in the acid copolymer is typically from 0 wt. % to 50 wt. %,preferably from 5 wt. % to 40 wt. %, more preferably from 10 wt. % to 35wt. %, and even more preferably from 20 wt. % to 30 wt. %, based ontotal weight of the copolymer. “Low acid” and “high acid” ionomericpolymers, as well as blends of such ionomers, may be used. In general,low acid ionomers are considered to be those containing 16 wt. % or lessof acid moieties, whereas high acid ionomers are considered to be thosecontaining greater than 16 wt. % of acid moieties.

The various O/X, E/X, O/X/Y, and E/X/Y-type copolymers are at leastpartially neutralized with a cation source, optionally in the presenceof a high molecular weight organic acid, such as those disclosed in U.S.Pat. No. 6,756,436, the entire disclosure of which is herebyincorporated herein by reference. The acid copolymer can be reacted withthe optional high molecular weight organic acid and the cation sourcesimultaneously, or prior to the addition of the cation source. Suitablecation sources include, but are not limited to, metal ion sources, suchas compounds of alkali metals, alkaline earth metals, transition metals,and rare earth elements; ammonium salts and monoamine salts; andcombinations thereof. Preferred cation sources are compounds ofmagnesium, sodium, potassium, cesium, calcium, barium, manganese,copper, zinc, lead, tin, aluminum, nickel, chromium, lithium, and rareearth metals.

Meanwhile, the thermoplastic polymer of the inventive three-partthermoplastic blend may comprise at least one thermoplasticpolyurethane, thermoplastic urea, thermoplastic urea-urethane hybrid, orcombinations/blends thereof. In general, polyurethanes contain urethanelinkages formed by reacting an isocyanate group (—N═C═O) with a hydroxylgroup (OH). The polyurethanes are produced by the reaction of amulti-functional isocyanate (NCO—R—NCO) with a long-chain polyol havingterminal hydroxyl groups (OH—OH) in the presence of a catalyst and otheradditives. The chain length of the polyurethane prepolymer is extendedby reacting it with short-chain diols (OH—R′—OH). The resultingpolyurethane has elastomeric properties because of its “hard” and “soft”segments, which are covalently bonded together. This phase separationoccurs because the mainly non-polar, low melting soft segments areincompatible with the polar, high melting hard segments. The hardsegments, which are formed by the reaction of the diisocyanate and lowmolecular weight chain-extending diol, are relatively stiff andimmobile. The soft segments, which are formed by the reaction of thediisocyanate and long chain diol, are relatively flexible and mobile.Because the hard segments are covalently coupled to the soft segments,they inhibit plastic flow of the polymer chains, thus creatingelastomeric resiliency.

By the term, “isocyanate compound” as used herein, it is meant anyaliphatic or aromatic isocyanate containing two or more isocyanatefunctional groups. The isocyanate compounds can be monomers or monomericunits, because they can be polymerized to produce polymeric isocyanatescontaining two or more monomeric isocyanate repeat units. The isocyanatecompound may have any suitable backbone chain structure includingsaturated or unsaturated, and linear, branched, or cyclic. By the term,“polyamine” as used herein, it is meant any aliphatic or aromaticcompound containing two or more primary or secondary amine functionalgroups. The polyamine compound may have any suitable backbone chainstructure including saturated or unsaturated, and linear, branched, orcyclic. The term “polyamine” may be used interchangeably withamine-terminated component. By the term, “polyol” as used herein, it ismeant any aliphatic or aromatic compound containing two or more hydroxylfunctional groups. The term “polyol” may be used interchangeably withhydroxy-terminated component.

Thermoplastic polyurethanes have minimal cross-linking; any bonding inthe polymer network is primarily through hydrogen bonding or otherphysical mechanism. Because of their lower level of cross-linking,thermoplastic polyurethanes are relatively flexible. The cross-linkingbonds in thermoplastic polyurethanes can be reversibly broken byincreasing temperature such as during molding or extrusion. That is, thethermoplastic material softens when exposed to heat and returns to itsoriginal condition when cooled. On the other hand, thermosetpolyurethanes become irreversibly set when they are cured. Thecross-linking bonds are irreversibly set and are not broken when exposedto heat. Thus, thermoset polyurethanes, which typically have a highlevel of cross-linking, are relatively rigid.

Aromatic polyurethanes can be prepared in accordance with this inventionand these materials are preferably formed by reacting an aromaticdiisocyanate with a polyol. Suitable aromatic diisocyanates that may beused in accordance with this invention include, for example, toluene2,4-diisocyanate (TDI), toluene 2,6-diisocyanate (TDI), 4,4′-methylenediphenyl diisocyanate (MDI), 2,4′-methylene diphenyl diisocyanate (MDI),polymeric methylene diphenyl diisocyanate (PMDI), p-phenylenediisocyanate (PPDI), m-phenylene diisocyanate (PDI), naphthalene1,5-diisocynate (NDI), naphthalene 2,4-diisocyanate (NDI), p-xylenediisocyanate (XDI), and homopolymers and copolymers and blends thereof.The aromatic isocyanates are able to react with the hydroxyl or aminecompounds and form a durable and tough polymer having a high meltingpoint. The resulting polyurethane generally has good mechanical strengthand cut/shear-resistance.

Aliphatic polyurethanes also can be prepared in accordance with thisinvention and these materials are preferably formed by reacting analiphatic diisocyanate with a polyol. Suitable aliphatic diisocyanatesthat may be used in accordance with this invention include, for example,isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (HDI),4,4′-dicyclohexylmethane diisocyanate (“H₁₂ MDI”),meta-tetramethylxylyene diisocyanate (TMXDI), trans-cyclohexanediisocyanate (CHDI), and homopolymers and copolymers and blends thereof.Particularly suitable multi-functional isocyanates include trimers ofHDI or H₁₂ MDI, oligomers, or other derivatives thereof. The resultingpolyurethane generally has good light and thermal stability.

Any polyol available to one of ordinary skill in the art is suitable foruse according to the invention. Exemplary polyols include, but are notlimited to, polyether polyols, hydroxy-terminated polybutadiene(including partially/fully hydrogenated derivatives), polyester polyols,polycaprolactone polyols, and polycarbonate polyols. In one preferredembodiment, the polyol includes polyether polyol. Examples include, butare not limited to, polytetramethylene ether glycol (PTMEG) which isparticularly preferred, polyethylene propylene glycol, polyoxypropyleneglycol, and mixtures thereof. The hydrocarbon chain can have saturatedor unsaturated bonds and substituted or unsubstituted aromatic andcyclic groups.

In another embodiment, polyester polyols are included in thepolyurethane material. Suitable polyester polyols include, but are notlimited to, polyethylene adipate glycol; polybutylene adipate glycol;polyethylene propylene adipate glycol; o-phthalate-1,6-hexanediol;poly(hexamethylene adipate) glycol; and mixtures thereof. Thehydrocarbon chain can have saturated or unsaturated bonds, orsubstituted or unsubstituted aromatic and cyclic groups. In stillanother embodiment, polycaprolactone polyols are included in thematerials of the invention. Suitable polycaprolactone polyols include,but are not limited to: 1,6-hexanediol-initiated polycaprolactone,diethylene glycol initiated polycaprolactone, trimethylol propaneinitiated polycaprolactone, neopentyl glycol initiated polycaprolactone,1,4-butanediol-initiated polycaprolactone, and mixtures thereof. Thehydrocarbon chain can have saturated or unsaturated bonds, orsubstituted or unsubstituted aromatic and cyclic groups. In yet anotherembodiment, polycarbonate polyols are included in the polyurethanematerial of the invention. Suitable polycarbonates include, but are notlimited to, polyphthalate carbonate and poly(hexamethylene carbonate)glycol. The hydrocarbon chain can have saturated or unsaturated bonds,or substituted or unsubstituted aromatic and cyclic groups. In oneembodiment, the molecular weight of the polyol is from about 200 toabout 4000.

There are two basic techniques that can be used to make thepolyurethanes: a) one-shot technique, and b) prepolymer technique. Inthe one-shot technique, the diisocyanate, polyol, andhydroxyl-terminated chain-extender (curing agent) are reacted in onestep. On the other hand, the prepolymer technique involves a firstreaction between the diisocyanate and polyol compounds to produce apolyurethane prepolymer, and a subsequent reaction between theprepolymer and hydroxyl-terminated chain-extender. As a result of thereaction between the isocyanate and polyol compounds, there will be someunreacted NCO groups in the polyurethane prepolymer. The prepolymershould have less than 14% unreacted NCO groups. Preferably, theprepolymer has no greater than 8.5% unreacted NCO groups, morepreferably from 2.5% to 8%, and most preferably from 5.0% to 8.0%unreacted NCO groups. As the weight percent of unreacted isocyanategroups increases, the hardness of the composition also generallyincreases.

Either the one-shot or prepolymer method may be employed to produce thepolyurethane compositions of the invention. In one embodiment, theone-shot method is used, wherein the isocyanate compound is added to areaction vessel and then a curative mixture comprising the polyol andcuring agent is added to the reaction vessel. The components are mixedtogether so that the molar ratio of isocyanate groups to hydroxyl groupsis preferably in the range of about 1.00:1.00 to about 1.10:1.00. In asecond embodiment, the prepolymer method is used. In general, theprepolymer technique is preferred because it provides better control ofthe chemical reaction. The prepolymer method provides a more homogeneousmixture resulting in a more consistent polymer composition. The one-shotmethod results in a mixture that is inhomogeneous (more random) andaffords the manufacturer less control over the molecular structure ofthe resultant composition.

The polyurethane compositions can be formed by chain-extending thepolyurethane prepolymer with a single chain-extender or blend ofchain-extenders as described further below. As discussed above, thepolyurethane prepolymer can be chain-extended by reacting it with asingle chain-extender or blend of chain-extenders. In general, theprepolymer can be reacted with hydroxyl-terminated curing agents,amine-terminated curing agents, and mixtures thereof. The curing agentsextend the chain length of the prepolymer and build-up its molecularweight. In general, thermoplastic polyurethane compositions aretypically formed by reacting the isocyanate blend and polyols at a 1:1stoichiometric ratio. Thermoset compositions, on the other hand, arecross-linked polymers and are typically produced from the reaction ofthe isocyanate blend and polyols at normally a 1.05:1 stoichiometricratio

A catalyst may be employed to promote the reaction between theisocyanate and polyol compounds for producing the prepolymer or betweenprepolymer and chain-extender during the chain-extending step.Preferably, the catalyst is added to the reactants before producing theprepolymer. Suitable catalysts include, but are not limited to, bismuthcatalyst; zinc octoate; stannous octoate; tin catalysts such asbis-butyltin dilaurate, bis-butyltin diacetate, stannous octoate; tin(II) chloride, tin (IV) chloride, bis-butyltin dimethoxide,dimethyl-bis[1-oxonedecyl)oxy]stannane, di-n-octyltin bis-isooctylmercaptoacetate; amine catalysts such as triethylenediamine,triethylamine, and tributylamine; organic acids such as oleic acid andacetic acid; delayed catalysts; and mixtures thereof. The catalyst ispreferably added in an amount sufficient to catalyze the reaction of thecomponents in the reactive mixture. In one embodiment, the catalyst ispresent in an amount from about 0.001 percent to about 1 percent, andpreferably 0.1 to 0.5 percent, by weight of the composition.

The hydroxyl chain-extending (curing) agents are preferably selectedfrom the group consisting of ethylene glycol; diethylene glycol;polyethylene glycol; propylene glycol; 2-methyl-1,3-propanediol;2-methyl-1,4-butanediol; monoethanolamine; diethanolamine;triethanolamine; monoisopropanolamine; diisopropanolamine; dipropyleneglycol; polypropylene glycol; 1,2-butanediol; 1,3-butanediol;1,4-butanediol; 2,3-butanediol; 2,3-dimethyl-2,3-butanediol;trimethylolpropane; cyclohexyldimethylol; triisopropanolamine;N,N,N′,N′-tetra-(2-hydroxypropyl)-ethylene diamine; diethylene glycolbis-(aminopropyl) ether; 1,5-pentanediol; 1,6-hexanediol;1,3-bis-(2-hydroxyethoxy) cyclohexane; 1,4-cyclohexyldimethylol;1,3-bis-[2-(2-hydroxyethoxy) ethoxy]cyclohexane; 2,2′-(1,4-phenylenedioxy)diethanol, 1,3-bis-12-[2-(2-hydroxyethoxy)ethoxy[ethoxy}cyclohexane; trimethylolpropane; polytetramethylene etherglycol (PTMEG), preferably having a molecular weight from about 250 toabout 3900; and mixtures thereof.

Suitable amine chain-extending (curing) agents that can be used inchain-extending the polyurethane prepolymer include, but are not limitedto, unsaturated diamines such as 4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-dianiline or “MDA”), m-phenylenediamine,p-phenylenediamine, 1,2- or 1,4-bis(sec-butylamino)benzene,3,5-diethyl-(2,4- or 2,6-) toluenediamine or “DETDA”,3,5-dimethylthio-(2,4- or 2,6-)toluenediamine, 3,5-diethylthio-(2,4- or2,6-)toluenediamine, 3,3′-dimethyl-4,4′-diamino-diphenylmethane,3,3′-diethyl-5,5′-dimethyl4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-bis(2-ethyl-6-methyl-benezeneamine)),3,3′-dichloro-4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-bis(2-chloroaniline) or “MOCA”),3,3′,5,5′-tetraethyl-4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-bis(2,6-diethylaniline),2,2′-dichloro-3,3′,5,5′-tetraethyl-4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-bis(3-chloro-2,6-diethyleneaniline) or “MCDEA”),3,3′-diethyl-5,5′-dichloro-4,4′-diamino-diphenylmethane, or “MDEA”),3,3′-dichloro-2,2′,6,6′-tetraethyl-4,4′-diamino-diphenylmethane,3,3′-dichloro-4,4′-diamino-diphenylmethane,4,4′-methylene-bis(2,3-dichloroaniline) (i.e.,2,2′,3,3′-tetrachloro-4,4′-diamino-diphenylmethane or “MDCA”); andmixtures thereof. One particularly suitable amine-terminatedchain-extending agent is Ethacure 300™ (dimethylthiotoluenediamine or amixture of 2,6-diamino-3,5-dimethylthiotoluene and2,4-diamino-3,5-dimethylthiotoluene.) The amine curing agents used aschain extenders normally have a cyclic structure and a low molecularweight (250 or less).

When the polyurethane prepolymer is reacted with hydroxyl-terminatedcuring agents during the chain-extending step, as described above, theresulting polyurethane composition contains urethane linkages. On theother hand, when the polyurethane prepolymer is reacted withamine-terminated curing agents during the chain-extending step, anyexcess isocyanate groups in the prepolymer will react with the aminegroups in the curing agent. The resulting polyurethane compositioncontains urethane and urea linkages and may be referred to as apolyurethane/urea hybrid. The concentration of urethane and urealinkages in the hybrid composition may vary. In general, the hybridcomposition may contain a mixture of about 10 to 90% urethane and about90 to 10% urea linkages.

More particularly, when the polyurethane prepolymer is reacted withhydroxyl-terminated curing agents during the chain-extending step, asdescribed above, the resulting composition is essentially a purepolyurethane composition containing urethane linkages having thefollowing general structure:

where x is the chain length, i.e., about 1 or greater, and R and R₁ arestraight chain or branched hydrocarbon chain having about 1 to about 20carbons.

However, when the polyurethane prepolymer is reacted with anamine-terminated curing agent during the chain-extending step, anyexcess isocyanate groups in the prepolymer will react with the aminegroups in the curing agent and create urea linkages having the followinggeneral structure:

where x is the chain length, i.e., about 1 or greater, and R and R₁ arestraight chain or branched hydrocarbon chain having about 1 to about 20carbons.

The polyurethane compositions used to form the cover layer may containother polymer materials including, for example: aliphatic or aromaticpolyurethanes, aliphatic or aromatic polyureas, aliphatic or aromaticpolyurethane/urea hybrids, olefin-based copolymer ionomer compositions,polyethylene, including, for example, low density polyethylene, linearlow density polyethylene, and high density polyethylene; polypropylene;rubber-toughened olefin polymers; acid copolymers, for example,poly(meth)acrylic acid, which do not become part of an ionomericcopolymer; plastomers; flexomers; styrene/butadiene/styrene blockcopolymers; styrene/ethylene-butylene/styrene block copolymers;dynamically vulcanized elastomers; copolymers of ethylene and vinylacetates; copolymers of ethylene and methyl acrylates; polyvinylchloride resins; polyamides, poly(amide-ester) elastomers, and graftcopolymers of ionomer and polyamide including, for example, Pebax®thermoplastic polyether block amides, available from Arkema Inc;cross-linked trans-polyisoprene and blends thereof; polyester-basedthermoplastic elastomers, such as Hytrel®, available from DuPont;polyurethane-based thermoplastic elastomers, such as Elastollan®,available from BASF; polycarbonate/polyester blends such as Xylex®,available from SABIC Innovative Plastics; maleic anhydride-graftedpolymers such as Fusabone®, available from DuPont; and mixtures of theforegoing materials. In addition, the polyurethane compositions maycontain fillers, additives, and other ingredients that do not detractfrom the properties of the final composition. These additional materialsinclude, but are not limited to, catalysts, wetting agents, coloringagents, optical brighteners, cross-linking agents, whitening agents suchas titanium dioxide and zinc oxide, ultraviolet (UV) light absorbers,hindered amine light stabilizers, defoaming agents, processing aids,surfactants, and other conventional additives. Other suitable additivesinclude antioxidants, stabilizers, softening agents, plasticizers,including internal and external plasticizers, impact modifiers, foamingagents, density-adjusting fillers, reinforcing materials,compatibilizers, and the like. Some examples of useful fillers includezinc oxide, zinc sulfate, barium carbonate, barium sulfate, calciumoxide, calcium carbonate, clay, tungsten, tungsten carbide, silica, andmixtures thereof. Rubber regrind (recycled core material) and polymeric,ceramic, metal, and glass microspheres also may be used. Generally, theadditives will be present in the composition in an amount between about1 and about 70 weight percent based on total weight of the compositiondepending upon the desired properties.

Thermoplastic polyurea compositions are typically formed by reacting theisocyanate blend and polyamines at a 1:1 stoichiometric ratio. Thepolyurea prepolymer can be chain-extended by reacting it with a singlecuring agent or blend of curing agents. In general, the prepolymer canbe reacted with hydroxyl-terminated curing agents, amine-terminatedcuring agents, or mixtures thereof. The curing agents extend the chainlength of the prepolymer and build-up its molecular weight. Normally,the prepolymer and curing agent are mixed so the isocyanate groups andhydroxyl or amine groups are mixed at a 1.05:1.00 stoichiometric ratio.

A catalyst may be employed to promote the reaction between theisocyanate and polyamine compounds for producing the prepolymer orbetween prepolymer and curing agent during the chain-extending step.Preferably, the catalyst is added to the reactants before producing theprepolymer. Suitable catalysts include, but are not limited to, thoseidentified above in connection with promoting the reaction between theisocyanate and polyol compounds for producing the prepolymer or betweenprepolymer and chain-extender during the chain-extending step.

The hydroxyl chain-extending (curing) agents are preferably selectedfrom the same group identified above in connection with polyurethanecompositions.

Suitable amine chain-extending (curing) agents that can be used inchain-extending the polyurea prepolymer of this invention include, butare not limited to those identified above in connection withchain-extending the polyurethane prepolymer, as well as4,4′-bis(sec-butylamino)-diphenylmethane,N,N′-dialkylamino-diphenylmethane,trimethyleneglycol-di(p-aminobenzoate),polyethyleneglycol-di(p-aminobenzoate),polytetramethyleneglycol-di(p-aminobenzoate); saturated diamines such asethylene diamine, 1,3-propylene diamine, 2-methyl-pentamethylenediamine, hexamethylene diamine, 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine, imino-bis(propylamine), imido-bis(propylamine),methylimino-bis(propylamine) (i.e.,N-(3-aminopropyl)-N-methyl-1,3-propanediamine),1,4-bis(3-aminopropoxy)butane (i.e.,3,3′-[1,4-butanediylbis-(oxy)bis]-1-propanamine),diethyleneglycol-bis(propylamine) (i.e.,diethyleneglycol-di(aminopropyl)ether),4,7,10-trioxatridecane-1,13-diamine, 1-methyl-2,6-diamino-cyclohexane,1,4-diamino-cyclohexane, poly(oxyethylene-oxypropylene) diamines, 1,3-or 1,4-bis(methylamino)-cyclohexane, isophorone diamine, 1,2- or1,4-bis(sec-butylamino)-cyclohexane, N,N′-diisopropyl-isophoronediamine, 4,4′-diamino-dicyclohexylmethane,3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane,3,3′-dichloro-4,4′-diamino-dicyclohexylmethane,N,N′-dialkylamino-dicyclohexylmethane, polyoxyethylene diamines,3,3′-diethyl-5,5′-dimethyl-4,4′-diamino-dicyclohexylmethane,polyoxypropylene diamines,3,3′-diethyl-5,5′-dichloro-4,4′-diamino-dicyclohexylmethane,polytetramethylene ether diamines,3,3′,5,5′-tetraethyl-4,4′-diamino-dicyclohexylmethane (i.e.,4,4′-methylene-bis(2,6-diethylaminocyclohexane)),3,3′-dichloro-4,4′-diamino-dicyclohexylmethane,2,2′-dichloro-3,3′,5,5′-tetraethyl-4,4′-diamino-dicyclohexylmethane,(ethylene oxide)-capped polyoxypropylene ether diamines,2,2′,3,3′-tetrachloro-4,4′-diamino-dicyclohexylmethane,4,4′-bis(sec-butylamino)-dicyclohexylmethane; triamines such asdiethylene triamine, dipropylene triamine, (propylene oxide)-basedtriamines (i.e., polyoxypropylene triamines),N-(2-aminoethyl)-1,3-propylenediamine (i.e., N₃-amine), glycerin-basedtriamines, (all saturated); tetramines such asN,N′-bis(3-aminopropyl)ethylene diamine (i.e., N₄-amine) (bothsaturated), triethylene tetramine; and other polyamines such astetraethylene pentamine (also saturated).

When the polyurea prepolymer is reacted with amine-terminated curingagents during the chain-extending step, as described above, theresulting composition is essentially a pure polyurea composition. On theother hand, when the polyurea prepolymer is reacted with ahydroxyl-terminated curing agent during the chain-extending step, anyexcess isocyanate groups in the prepolymer will react with the hydroxylgroups in the curing agent and create urethane linkages to form apolyurea-urethane hybrid. Herein, the terms urea and polyurea are usedinterchangeably.

This chain-extending step, which occurs when the polyurea prepolymer isreacted with hydroxyl curing agents, amine curing agents, or mixturesthereof, builds-up the molecular weight and extends the chain length ofthe prepolymer. When the polyurea prepolymer is reacted with aminecuring agents, a polyurea composition having urea linkages is produced.When the polyurea prepolymer is reacted with hydroxyl curing agents, apolyurea/urethane hybrid composition containing both urea and urethanelinkages is produced. The polyurea/urethane hybrid composition isdistinct from the pure polyurea composition. The concentration of ureaand urethane linkages in the hybrid composition may vary. In general,the hybrid composition may contain a mixture of about 10 to 90% urea andabout 90 to 10% urethane linkages. The resulting polyurea orpolyurea/urethane hybrid composition has elastomeric properties based onphase separation of the soft and hard segments. The soft segments, whichare formed from the polyamine reactants, are generally flexible andmobile, while the hard segments, which are formed from the isocyanatesand chain extenders, are generally stiff and immobile.

Acrylonitrile styrene acrylate (ASA) is sometimes also called acrylicstyrene acrylonitrile, is a thermoplastic developed as an alternative toacrylonitrile butadiene styrene (ABS), and has good weather resistance.Preferred ABS and ASA grades have high “rubbery” content (high B in ABSor high acrylate in ASA). Commercially available ABS examples includeBlendex 338,374,362 and 3160 containing about 70, 70, 60, and 60%butadiene respectively. Commercially available ASA examples includeRoyaltuf 960A (60% nba) 945A and 984 (45% nba). These are available fromGalata Chemicals LLC.

The ionomer, thermoplastic polymer, and ASA and/or ABS may be mixed orotherwise combined and molded using any method known to one of ordinaryskill in the art. In this regard, these ingredients can be added into amaster batch simultaneously or sequentially, prior to molding.Alternatively, one or more of these ingredients may be combined first,and then added to the remaining ingredient(s). Compression andinjection-molding, retractable pin injection-molding (RPIM) methods,reaction injection-molding (RIM), liquid injection-molding, casting, andthe like may be used. Embodiments are also envisioned wherein the layerof three-part thermoplastic blend is formed about a subassembly byspraying, powder-coating, vacuum-forming, flow-coating, dipping, and/orspin-coating.

Many desirable golf ball constructions are possible incorporating atleast one layer of three-part thermoplastic blend having propertygradients within the at least one layer and between that layer andadjacent and nonadjacent layers.

Property gradients can be created within the at least one layer. Forexample, when the at least one layer is a layer surrounding aspherically-shaped subassembly, the at least one layer can have an innersurface hardness that differs from an outer surface hardness by up toabout 30 Shore A hardness points. In one such embodiment, the innersurface hardness and outer surface hardness may differ by up to about 5Shore A hardness points. In another embodiment, the inner surfacehardness and outer surface hardness may differ by up to about 10 Shore Ahardness points. In yet another embodiment, the inner surface hardnessand outer surface hardness may differ by up to about 15 Shore A hardnesspoints. In still another embodiment, the inner surface hardness andouter surface hardness may differ by up to about 20 Shore A hardnesspoints. In other embodiments, the inner surface hardness and outersurface hardness may differ by between 2 and 10 Shore A hardness points,or between 2 and 10 Shore A hardness points, or between 2 and 10 Shore Ahardness points, or between 5 and 15 Shore A hardness points, or between10 and 20 Shore A hardness points, or between 15 and 25 Shore A hardnesspoints, or from 20 to about 30 Shore A hardness points.

In such embodiments, the subassembly may have a geometric centerhardness and a subassembly outer surface hardness that differ by up to 5Shore C hardness points, or by up to 15 Shore C hardness points, or from10 to about 30 Shore C hardness points.

Meanwhile, the outer surface hardness and subassembly outer surfacehardness may differ by up to Shore D hardness points, or up to 10 ShoreD hardness points, or from about 5 to about 10 shore D hardness points,or from 5 Shore D to about 15 Shore D hardness points, or from about 10shore D to about 25 Shore D hardness points, or from 20 shore D hardnesspoints to about 35 Shore D hardness points, or by from about 30 Shore Dto about 50 Shore D hardness points, or by 40 to about 55 Shore Dhardness points.

In some embodiments, the outer surface may have a Shore D hardness offrom 20 to 70 and the geometric center has a Shore A hardness of from 65to 100. In other embodiments, the outer surface may have a Shore Ahardness of from 65 to 100 and the geometric center has a Shore Dhardness of from 20 to 70. In one alternative embodiment, the outersurface may have a Shore A hardness of from 75 to 100 and the geometriccenter may have a Shore D hardness of from 20 to 40. In anotheralternative embodiment, the outer surface may have a Shore A hardness offrom 75 to 100 and the geometric center may have a Shore D hardness offrom 20 to 40. In yet another alternative embodiment, the outer surfacemay have a Shore A hardness of from 85 to 100 and the geometric centermay have a Shore D hardness of from 40 to 60. In still anotheralternative embodiment, the outer surface may have a Shore A hardness offrom 90 to 100 and the geometric center may have a Shore D hardness offrom 50 to 70.

In embodiments wherein the three-part thermoplastic blend is a sphericalcore component of the golf ball, the core may have a material hardnessof from about 20 Shore D to about 70 Shore D, or from about 40 Shore Dto about 60 Shore D, or from about 20 Shore D to about 55 Shore D, orfrom about 20 Shore D to about 45 Shore D, or from about 35 Shore D toabout 65 Shore D, or from about 55 Shore D to about 70 Shore D.

In other embodiments wherein the three-part thermoplastic blend is aspherical core component of the golf ball, the core may have a Shore Ahardness of from about 60 to 100, or from about 65 to about 95, or fromabout 70 to about 90, or from about 65 to about 86, or from 75 to 100 orfrom 80 to 100, or from 90 to 100.

In one embodiment, the hardness of the three-part thermoplastic blenddiffers from a hardness of an outer surface of at least one other layerto define a negative or positive hardness gradient of up to Shore Dhardness points. In another embodiment, the hardness of the three-partthermoplastic blend differs from a hardness of an outer surface of atleast one other layer to define a negative or positive hardness gradientof between 1 and 5 Shore D hardness points. In yet another embodiment,the hardness of the three-part thermoplastic blend differs from ahardness of an outer surface of at least one other layer to define anegative or positive hardness gradient of greater than 5 and up to about20 Shore D hardness points. In still another embodiment, the hardness ofthe three-part thermoplastic blend differs from a hardness of an outersurface of at least one other layer to define a negative or positivehardness gradient of greater than 20 and up to about 45 Shore D hardnesspoints. In an alternative embodiment, the hardness of the three-partthermoplastic blend differs from a hardness of an outer surface of atleast one other layer to define a negative or positive hardness gradientof greater than 25 and up to about 50 Shore D hardness points.

In alternative embodiments, a layer of three-part thermoplastic blendmay be included in a golf ball of the invention as a single, solid corehaving a “positive” or “negative” hardness gradient, or as a “dualcore,” in which at least one of the inner core and outer core layerincorporates three-part thermoplastic material and has a positive ornegative hardness gradient.

Examples of “positive” hardness gradient embodiments, wherein a singlesolid core includes the three-part thermoplastic blend, are as follows:the surface hardness of the core can range from 25 Shore D to 90 ShoreD, or from 45 Shore D to 70 Shore D. In particular embodiments, thesurface hardness be 68 Shore D, 60 Shore D, or 49 Shore D. Thecorresponding hardness of the center of the solid core may range from 30Shore D to 80 Shore D, or from 40 Shore D to 65 Shore D, or inparticular embodiments, be 61 Shore D, 52 Shore D, or 43 Shore D,respectively.

Examples of “negative” hardness gradient embodiments, wherein a singlesolid core includes three-part thermoplastic blend, are as follows: thesurface hardness of the core can range from 20 Shore D to 80 Shore D, orfrom 35 Shore D to 60 Shore D, and in particular embodiments, thesurface hardness may be 56 Shore D, 45 Shore D, or 40 Shore D. Thecorresponding center hardness may range from 30 Shore D to 75 Shore D,or from 40 Shore D to 65 Shore D, or in particular embodiments, be 61Shore D, 52 Shore D, or 43 Shore D, respectively.

In a dual core “low spin” embodiment, the inner surface of the outercore layer is harder than the outer surface of the inner core. In a dualcore “high spin” embodiment, the inner surface of the outer core layeris softer than the outer surface of the inner core.

Examples of “positive” hardness gradient embodiments, wherein at leastone layer of the dual core includes three-part thermoplastic blend, areas follows: the outer core surface hardness may range from 25 Shore D to90 Shore D, or from 45 Shore D to 70 Shore D, and in particularembodiments, be 68 Shore D, 61 Shore D, or 49 Shore D. The inner surfaceof the outer core may have a corresponding hardness of 61 Shore D, 61Shore D, or 43 Shore D, respectively. The surface of the inner core canrange from 40 Shore D to 65 Shore D, or in particular embodiments be 43Shore D, 60 Shore D, or 49 Shore D, respectively. The center hardness ofthe inner core can range from 30 Shore D to 80 Shore D, or from 40 ShoreD to 55 Shore D, in particular embodiments be 43 Shore D, 50 Shore D, or43 Shore D, respectively.

Examples of “Negative” hardness gradient embodiments, wherein at leastone layer of the dual core includes three-part thermoplastic blend, areas follows: the outer core surface hardness may range from 20 Shore D to80 Shore D, or from 35 Shore D to 55 Shore D, or in particularembodiments, be 45 Shore D, 40 Shore D, or 52 Shore D. The inner surfaceof the outer core may have a corresponding hardness of 52 Shore D, 43Shore D, or 52 Shore D, respectively. The surface of the inner core canrange from 30 Shore D to 75 Shore D, or from 50 Shore D to 65 Shore D,or in particular embodiments be 61 Shore D, 52 Shore D, or 56 Shore D,respectively. The center hardness of the inner core can range from 50Shore D to 65 Shore D, or in particular embodiments be 61 Shore D, 52Shore D, or 61 Shore D, respectively. The “negative” gradient is steep.

In a “low spin” embodiment of the present invention, the hardness of aninner core (at any point—surface, center, or otherwise) includingthree-part thermoplastic blend may range from 30 Shore C to 80 Shore C,or from 40 Shore C to 75 Shore C, or from 45 Shore C to 70 Shore C.Concurrently, the hardness of the outer core layer (at anypoint—surface, inner surface, or otherwise) may range from 60 Shore C to95 Shore C, or from 60 Shore C to 90 Shore C, or from 65 Shore C to 80Shore C.

In a different “low spin” embodiment of the present invention, thehardness of an inner core (at any point—surface, center, or otherwise)including three-part thermoplastic blend may range from 30 Shore C to 80Shore C, or from 40 Shore C to 75 Shore C, or from 45 Shore C to 70Shore C. Concurrently, the hardness of the outer core layer (at anypoint—surface, inner surface, or otherwise) including three-partthermoplastic blend ranges from 60 Shore C to 95 Shore C, or from 60Shore C to 90 Shore C, or from 65 Shore C to 80 Shore C.

In an alternative “low spin” embodiment of the present invention, thehardness of an inner core (at any point—surface, center, or otherwise)including three-part thermoplastic blend may range from 30 Shore C to 80Shore C, or from 40 Shore C to 75 Shore C, or from 45 Shore C to 70Shore C. Concurrently, the hardness of the outer core layer (at anypoint—surface, inner surface, or otherwise) including three-partthermoplastic blend may range from 60 Shore C to 95 Shore C, or from 60Shore C to 90 Shore C, or from 65 Shore C to 80 Shore C.

In a “high spin” embodiment, the hardness of an inner core includingthree-part thermoplastic blend may range from 60 Shore C to 95 Shore C,or from 60 Shore C to 90 Shore C, or from 65 Shore C to 80 Shore C.Concurrently, the hardness of the outer core layer including three-partthermoplastic blend may range from 30 Shore C to 80 Shore C, or from 40Shore C to 75 Shore C, or from 45 Shore C to 70 Shore C.

In a different “high spin” embodiment, the hardness of an inner coreincluding three-part thermoplastic blend may range from 60 Shore C to 95Shore C, or from 60 Shore C to 90 Shore C, or from 65 Shore C to 80Shore C. Concurrently, the hardness of the outer core layer, includingthree-part thermoplastic blend, may range from 30 Shore C to 80 Shore C,or from 40 Shore C to 75 Shore C, or from 45 Shore C to 70 Shore C.

In an alternative “high spin” embodiment, the hardness of an inner coreincluding three-part thermoplastic blend may range from 60 Shore C to 95Shore C, or from 60 Shore C to 90 Shore C, or from 65 Shore C to 80Shore C. Concurrently, the hardness of the outer core layer, includingthree-part thermoplastic blend, may range from 30 Shore C to 80 Shore C,or from 40 Shore C to 75 Shore C, or from 45 Shore C to 70 Shore C.

The property gradient may also be a percent (%) neutralization gradientthat is created between an inner surface and outer surface of the atleast one layer of three-part thermoplastic blend, or alternatively,gradually develops from outer surface toward inner surface of the atleast one layer of three-part thermoplastic blend.

In different embodiments, at least one layer of the golf ball maycomprise a three-part thermoplastic blend consisting of: (i) at leastone ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or combination thereof; and(iii) a plurality of core-shell polymers; wherein at least one of a coreand a shell of each core-shell polymer comprises one or more polymethyl(meth) acrylate-based copolymer. The thermoplastic blend includes (i),(ii), and (iii) in a wt % ratio I:T:C; wherein I is the wt % of ionomer,T is the wt % of different thermoplastic polymer, and C is the wt % ofcore-shell polymer; and wherein I is >45 and 2≤C<35.

Each core-shell polymer may have a diameter of from about 0.5 microns toabout 20.0 microns. In a particular embodiment, each core-shell polymerhas a diameter of from about 0.05 microns to about 0.20 micron.

In one embodiment, at least one core-shell polymer of the plurality hasa urethane-containing core. In another embodiment, at least onecore-shell polymer of the plurality has a non-urethane-containing core.

In another embodiment, at least one layer may comprise a three-partthermoplastic blend consisting of: (i) at least one ionomer; (ii) atleast one different thermoplastic polymer consisting of at least onethermoplastic polyurethane, thermoplastic urea, thermoplasticurea-urethane hybrid, or combination thereof; and (iii) at least onepolymethyl (meth)acrylate-based copolymer. The three-part thermoplasticblend includes (i), (ii), and (iii) in a wt % ratio I:T:C; wherein I isthe wt % of ionomer, T is the wt % of different thermoplastic polymer,and C is the wt % of polymethyl (meth)acrylate-based copolymer; andwherein I is >45 and 2≤C<35. In some embodiments, at least one layer mayconsist of a three-part thermoplastic blend consisting of: (i) at leastone ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or combination thereof; and(iii) a plurality of core-shell polymers; wherein at least one of a coreand a shell of each core-shell polymer comprises one or more polymethyl(meth)acrylate-based copolymer. And in other embodiments, at least onelayer may consist of a three-part thermoplastic blend consisting of: (i)at least one ionomer; (ii) at least one different thermoplastic polymerconsisting of at least one thermoplastic polyurethane, thermoplasticurea, thermoplastic urea-urethane hybrid, or combination thereof; and(iii) at least one polymethyl (meth) acrylate-based copolymer.

In such embodiments, the polymethyl (meth)acrylate-based copolymer maybe selected from the group consisting of polymethyl(meth)acrylate-based-n-butyl acrylate; polymethyl(meth)acrylate-based-ethyl acrylate; polymethyl(meth)acrylate-based-n-butyl acrylate-styrene; polymethyl(meth)acrylate-based-butadiene-styrene; polymethyl(meth)acrylate-based-acyrlonitrile-butadiene-styrene; polymethyl(meth)acrylate-based-ethylene-propylene-diene (EPDM); polymethyl(meth)acrylate-based-EPDM-styrene; polymethyl(meth)acrylate-based-glycidyl methacrylate-ethyl acrylate; polymethyl(meth)acrylate-based-glycidyl; (meth)acrylate-n-butyl acrylate;polymethyl (meth)acrylate-based-styrene-acrylonitrile; polymethyl(meth)acrylate-based-butadiene; and combinations thereof.

The polymethyl (meth)acrylate-based copolymer may comprise(meth)acrylates selected from the group consisting of: (meth)acrylatesderived from saturated alcohols; (meth)acrylates derived fromunsaturated alcohols; aryl(meth)acrylates; cycloalkyl(meth)acrylates;hydroxyalkyl(meth)acrylates; glycol di(methacrylates); (meth)acrylatesof ether alcohols; amides of (meth)acrylic acid; nitriles of(meth)acrylic acid; sulfur-containing (meth)acrylates; polyfunctional(meth)acrylates; and combinations thereof.

The polymethyl (meth)acrylate-based copolymer may comprise acrylatesselected from the group consisting of methyl acrylate, ethyl acrylate,propyl acrylate, iso-butyl acrylate, n-butyl acrylate, n-amyl acrylate,n-hexyl acrylate, isohexyl acrylates, n-heptyl acrylate, isoheptylacrylates, capryl acrylate, (1-methylheptyl acrylate), n-octyl acrylate,ethylhexyl acrylate, isooctyl acrylates, methylheptyl acrylate, n-nonylacrylate, isononyl acrylates, 3,5,5-trimethylhexyl acrylate, n-decylacrylate, lauryl acrylate, n-amyl acrylate, n-hexyl acrylate, caprylacrylate (1-methylheptyl acrylate), n-octyl acrylate, isooctyl acrylatessuch as n-methylheptyl acrylate, 2-ethylhexyl acrylate, capryl acrylate.

The polymethyl (meth)acrylate-based copolymer may comprise a comonomerselected from the group consisting of: 1-alkenes; branched alkenes;acrylonitrile; styrenes; maleic acid derivatives; dienes; andcombinations thereof.

The polymethyl (meth)acrylate-based copolymer may be selected from thegroup consisting of: alternating polymethyl (meth)acrylate-basedcopolymers, block polymethyl (meth)acrylate-based copolymers, randompolymethyl (meth)acrylate-based copolymers, graft polymethyl(meth)acrylate-based copolymers, gradient polymethyl(meth)acrylate-based copolymers, and combinations thereof.

A thermoplastic polymer herein may further compriseacrylonitrile-butadiene-styrene terpolymer,acrylonitrile-styrene-acrylate, acrylonitrile-ethylene-styreneterpolymer, styrene acrylonitrile copolymer, styrene maleic anhydridecopolymer, or combinations thereof.

A thermoplastic polymer herein may further comprise polycarbonate,maleic anhydride, grafted maleic anhydride, glycidyl methacrylate,modified polyolefins, modified styrene copolymers, or combinationsthereof.

A thermoplastic polymer herein may include a modified styrene copolymerselected from the group consisting of poly(styrene-butadiene-styrene),poly(styrene-isoprene-styrene), poly(styrene-ethylene/butylene-styrene),and poly(styrene-ethylene/propylene-styrene).

In some embodiments, the tri-part thermoplastic blend may have a glasstransition temperature Tg-b that is greater than a glass transitiontemperature Tg-tp of the thermoplastic polymer.

As used herein, the term polymethyl methacrylate-based copolymer or MMAcopolymer comprises poly(meth)acrylates, methacrylates, and acrylates.Polymethacrylates can be obtained using known methods such as viafree-radical polymerization of (meth)acrylates. Herein, the terms(meth)acrylate and methacrylate are used interchangeably.

The term “alternating” means that the MMA copolymer is comprised ofalternating sequences of different monomers in a roughly 1 to 1 ratio.The term “block” means that the MMA copolymer is comprised of relativelylong sequences of one monomer followed by a relatively long sequence ofa different monomer. The term “random” means that the MMA copolymer iscomprised of two or more different repeating units of (2 or more)monomers are distributed randomly. The term “graft” means that the MMAcopolymer is comprised of a main chain of one type of monomer withbranches of another type of monomer. The term “gradient” means that theMMA copolymer exhibits a gradual change in composition along the chainfrom mostly one type of monomer at the start of a chain to mostlyanother type at the chain end. More specific variations within some ofthese groups include, for example, star, comb, and/or centipedeconfigurations.

The thermoplastic polymer and MMA copolymer may be mixed and moldedusing any method known to one of ordinary skill in the art. In thisregard, the MMA copolymer may be incorporated into a master batch whichis then added to the thermoplastic polymer prior to molding.Alternatively, the thermoplastic polymer and MMA copolymer may becombined by at least one of high shear mixing, followed by molding.Compression and injection-molding, retractable pin injection-molding(RPIM) methods, reaction injection-molding (RIM), liquidinjection-molding, casting, and the like may be used. Embodiments arealso envisioned wherein the layer of inventive three-part thermoplasticblend is formed about a subassembly by spraying, powder-coating,vacuum-forming, flow-coating, dipping, and/or spin-coating.

As used herein, the phrase “plurality of core-shell polymers” refers tothe group or loading of core-shell polymers being combined with theionomer and thermoplastic polymer to form the three-part thermoplasticblend. In one embodiment, all core-shell polymers of a particular groupor loading may be substantially similar both with respect toconstruction (shape/size) and composition. In other embodiments, atleast two core-shell polymers of the group or loading may differ, suchas having different core sizes/shapes and/or compositions and/or havingdiffering shell sizes/shapes and/or compositions.

The loading of the plurality of core-shells can be adjusted to modifyresulting layer properties such as material hardness, flexural modulus,tensile strength and target mechanical strength, impact durability, andshear-resistance and will depend at least in part on the particularproperties of the specific thermoplastic polymer being combinedtherewith.

Each core-shell may have a diameter of from about 0.05 microns to about20 microns. In one embodiment, each core-shell polymer may have adiameter of from about 0.5 microns to about 20.0 microns. In anotherembodiment, each core-shell polymer has a diameter of from about 0.05microns to about 0.20 microns.

In one embodiment, at least one core-shell polymer of the plurality hasa urethane-containing core. In another embodiment, at least onecore-shell polymer of the plurality has a non-urethane-containing core.

The invention also relates to a method of making a golf ball of theinvention, comprising: providing a subassembly; and forming at least onelayer about the subassembly consisting of a three-part thermoplasticblend of (i) ionomer(s); (ii) a thermoplastic polymer; and (iii) (a) aplurality of core-shell polymers; wherein at least one of a core and ashell of each core-shell polymer comprises one or more polymethyl(meth)acrylate-based copolymer; and/or (b) at least one polymethyl(meth)acrylate-based copolymer; wherein the thermoplastic polymercomprises at least one thermoplastic polyurethane, thermoplastic urea,thermoplastic urea-urethane hybrid, or combinations thereof.

In other embodiments, the method comprises providing a subassemblyconsisting of (i) ionomer(s); (ii) a thermoplastic polymer; and (iii)(a)a plurality of core-shell polymers; wherein at least one of a core and ashell of each core-shell polymer comprises one or more polymethyl(meth)acrylate-based copolymer; and/or (b) at least one polymethyl(meth)acrylate-based copolymer; wherein the thermoplastic polymercomprises at least one thermoplastic polyurethane, thermoplastic urea,thermoplastic urea-urethane hybrid, or combinations thereof; and formingat least one layer comprising a thermoset or thermoplastic compositionabout the subassembly.

Core-shell polymers can be prepared by methods such as dispersion,precipitation, and emulsion polymerization. See, e.g., “Core-shellpolymers: a review”, Ramli, Ros Azlinawati; Laftah, Waham Ashaier;Hashim, Shahrir; RSC Advances, 2013, 3, 15543-15565 (hereinafterreferred to as “the core-shell polymer review article”), herebyincorporated by reference herein in its entirety.

Non-limiting examples of suitable core-shell polymers includeRayAce®5525, RayCore®9534A, RayCore®9507A, RayCore®9506A, andRayCore®9021A, all commercially available from Specialty Polymers, Inc.RayAce®5525 core-shells are alkyd-acrylic core-shell hybrids havingaverage particle sizes of 0.16 micron, and RayCore®9534A, RayCore®9507A,RayCore®9506A, and RayCore®9021A are urethane-acrylic core-shell hybridshaving average particle sizes of 0.10 microns. Additional examples ofcore-shell constructions include those disclosed and described in U.S.Pat. No. 4,419,471 of Nelsen et al.; U.S. Pat. No. 4,666,777 of Ash etal.; U.S. Pat. No. 4,876,313 of Lorah; U.S. Pat. No. 5,006,592 of Oshimaet al.; U.S. Pat. No. 5,183,858 of Sasaki et al.; U.S. Pat. No.5,206,299 of Oshima et al.; U.S. Pat. No. 5,237,015 of Urban; U.S. Pat.No. 5,242,982 of Oshima et al.; U.S. Pat. No. 5,280,075 of Oshima etal.; U.S. Pat. No. 5,280,076 of Sasaki et al.; U.S. Pat. No. 5,290,858of Sasaki et al.; U.S. Pat. No. 5,304,707 of Blankenship et al.; U.S.Pat. No. 5,324,780 of Oshima et al.; U.S. Pat. No. 5,362,804 of Oshimaet al.; U.S. Pat. No. 5,403,894 of Tsai et al.; U.S. Pat. No. 5,453,458of Takeuchi et al.; U.S. Pat. No. 6,777,500 of Lean et al.; and U.S.Pat. No. 6,858,301 of Ganapathiappan, each of which is herebyincorporated herein in its entirety.

Advantageously, the inventive three-part thermoplastic blend may have aglass transition temperature Tg-m that is greater than a glasstransition temperature Tg-tp of the thermoplastic polymer. In thisregard, the term Glass Transition Temperature (Tg) refers to thetemperature region where a polymer transitions from a hard, glassymaterial to a soft, rubbery material. It is always lower than themelting temperature of the crystalline state of the material, if oneexists. Tg can be measured by MDSC, which is an enhancement toconventional DSC [DSC measures the temperatures and heat flowsassociated with transitions in materials as a function of temperature ortime in a controlled atmosphere making a Differential Scanningcalorimetry (DSC) determination using a DSC calorimeter NETZSCH, type204].

MDSC separates the total heat flow into reversing (heat capacity) andnon-reversing (kinetic) components. The reversing signal contains heatcapacity events such as the glass transition and melting. Thenon-reversing signal contains kinetic events such as crystallization,crystal perfection and reorganization, cure, and decomposition.Instrumentation is also commercially available from TA Instruments.

In an inventive three-part thermoplastic blend of the invention,interactions between the thermoplastic polymer, having a relativelylower Tg, and a plurality of core-shell polymers, having a relativelyhigher Tg, create a resulting thermoplastic material having improvedmechanical strength, impact durability, and cut and scuff (grooveshear)-resistance, compared to a layer of thermoplastic polymer alone,and can better and more reliably sustain the great force and impact of aclub face sticking the golf ball on the course.

In this regard, TPU's generally have a Tg below 0° C. (32° F.), or −10°C. or less, or −30° C. or less, or −40° C. or less. Meanwhile the Tg ofand poly(methyl methacrylate) is well above room temperature, at around100 C (212° F.). Each core-shell polymer, containing poly(methylmethacrylate) in one of its core or shell and having a shell or coreformed of a different material, will have a Tg greater than that of thethermoplastic polymer and generally less than about 100° C. (212° F.).

In one specific example, a RayAce®5525 alkyd-acrylic core-shell hybridhas a Tg of about 29° C. (84.2° F.). In another specific example,urethane-acrylic core-shell hybrids RayCore®9534A, RayCore®9507A,RayCore®9506A, and RayCore®9021A have Tg's of 30° C. (86° F.), 42° C.(107.2° F.), 39° C. (102.2° F.), and 17° C. (60.8° F.), respectively.Thus, where the thermoplastic polyurethane is mixed with thesecore-shell polymers, a layer can be produced having desirably superiormechanical strength, impact durability, and cut and scuff (grooveshear)-resistance compared with the thermoplastic polyurethane.

In one embodiment, at least some of the core-shell polymers of theplurality will have a glass transition temperature Tg-cs that is greaterthan Tg-tp. In another embodiment, all of the core-shell polymers of theplurality will have a glass transition temperature Tg-cs that is greaterthan Tg-tp. In a particular embodiment, Tg-cs and Tg-tp differ by atleast 25° C.

Non-limiting examples of suitable MMA-comprising polymers forincorporation in core-shell constructions also include Blendex® 338,Blendex® 362, and Blendex® 3160, and Royaltuf®960A, commerciallyavailable from Galata Chemicals, LLC.

In one embodiment, the resulting layer contains a heterogeneousthree-part thermoplastic blend wherein a plurality of core-shellpolymers are located throughout the ionomer and thermoplasticpolyurethane polymer. In another embodiment, the resulting layercontains a heterogeneous three-part thermoplastic blend wherein aplurality of core-shell polymers are located throughout a thermoplasticpolyurea polymer. In yet another embodiment, the resulting layercontains a heterogeneous three-part thermoplastic blend wherein aplurality of core-shell polymers that are located throughout athermoplastic polyurethane-polyurea polymer.

In any of these embodiments, the plurality may include a plurality ofcore-shells that are substantially similar or alternatively include twoor more different core-shell types. For example, the plurality mayinclude both urethane-acrylic core-shell hybrids and alkyd-acryliccore-shell hybrids. Or, the plurality may include all urethane-acryliccore-shell hybrids but which have differing shell thicknesses.

In embodiments wherein the at least one core-shell polymer of theplurality has a urethane-containing core, that core may in oneembodiment be formed from the same polyurethane that the thermoplasticpolymer of the three-part thermoplastic blend is formed from. In othersuch embodiments, that core may be formed from a different polyurethanethan the thermoplastic polymer of the three-part thermoplastic blend isformed from.

In some embodiments, at least one core-shell polymer of the pluralityhas a non-urethane-containing core and it is envisioned that numerousnon-urethane compositions known in the art may form the core. Meanwhile,in each core-shell polymer of the plurality, at least one of a coreand/or shell comprises one or more polymethyl methacrylate (MMA)copolymers. Each core-shell polymer uniquely collectively contributes tothe resulting three-part thermoplastic blend properties not possessed bythe core or shell individually, which when further combined with thethermoplastic polymer of the three-part thermoplastic blend creates aresulting layer that is more durable and tough than the thermoplastic ofthe three-part thermoplastic blend alone.

Interactions between each of the plurality of core-shell polymers andthe thermoplastic polymer create a resulting thermoplastic materialhaving superior mechanical strength, impact durability, and cut andscuff (groove shear)-resistance compared to the thermoplastic polymeralone and can better and more reliably sustain the great force andimpact of a club face sticking the golf ball on the course.

The resulting three-part thermoplastic blend of the invention also mayhave a greater flexural modulus (ASTM D-790), tensile strength (ASTMD-638), and ultimate elongation (ASTM D-638) than the thermoplasticpolymer of the three-part thermoplastic blend. The relative amounts ofionomer, thermoplastic polymer and plurality of core-shell polymers canbe changed, coordinated and targeted to achieve desired Tg, flexuralmodulus, tensile strength and/or ultimate elongation of the layer ofthree-part thermoplastic blend.

In this regard, the resulting inventive three-part thermoplastic blendcan have a low flexural modulus or a high flexural modulus, as long asthe inventive three-part thermoplastic blend flexural modulus is greaterthan the flexural modulus of the thermoplastic polymer of the three-partthermoplastic blend. Thus, a layer of three-part thermoplastic blend mayfor example have a flexural modulus within a range having a lower limitof about 300 psi or 1,000 psi or 5,000 psi or 10,000 psi and an upperlimit of 15,000 or 20,000 or 25,000 or 30,000 or 35,000 or 45,000 or50,000 or 55,000 psi. In these embodiments, the flexural modulus of thethermoplastic polymer of the three-part thermoplastic blend may be atleast 5% less, 10% less, or at least 20% less, or at least 25% less, orat least 30% less, or at least 35% less, than that of the inventivethree-part thermoplastic blend.

Alternatively, the resulting inventive three-part thermoplastic blendmay have a high flexural modulus within a range having a lower limit ofabout 25,000 or 30,000 or 35,000 or 40,000 or 45,000 or 50,000 or 55,000or 60,000 psi and an upper limit of 70,000 or 75,000 or 100,000 or150,000 psi. In such embodiments, the modulus of the thermoplasticpolymer of the three-part thermoplastic blend may be at least 5% less,10% less, or at least 20% less, or at least 25% less, or at least 30%less, or at least 35% less, than that of the inventive three-partthermoplastic blend.

Additionally, the resulting inventive three-part thermoplastic blend canhave a low tensile strength or a high tensile strength, as long as theinventive three-part thermoplastic blend tensile strength is greaterthan the tensile strength of the thermoplastic polymer of the three-partthermoplastic blend. In one non-limiting example, the tensile strengthof the resulting layer may be greater than 4500 psi, or greater than5500 psi, or at least 6500 psi, or at least 7500 psi, or at least 8500psi, or at least 9500 psi.

Moreover, the resulting inventive three-part thermoplastic blend canhave a low ultimate elongation or a high ultimate elongation, as long asthe inventive three-part thermoplastic blend ultimate elongation isgreater than the ultimate elongation of the thermoplastic polymer of thethree-part thermoplastic blend. For example, the ultimate elongation maybe at least 25%, or at least 50%, or at least 100%, or at least 125%, orat least 150%, or at least 175%, or 200% or greater.

In some embodiments, the shell thickness of each core-shell polymer maybe targeted to create core-shell polymers that remain structurallyintact and well dispersed within the thermoplastic polymer during and/orafter melt blending. In such embodiments, a shell that is too thin maynot protect its core sufficiently during vigorous processing conditionswhich can result in the cores becoming partially exposed and connectingwith each other to form a cellular-like structure, thereby producingpoor toughening efficiency.

Meanwhile, if the shell of a core-shell polymer is too thick,insufficient elasticity may result in which case the core-shells becomeuseful in the inventive three-part thermoplastic blend as rigid fillers,rather than as an efficient impact modifier. Thus, regardless of theparticle size, shell thickness of these core-shell polymer can betargeted in order to display high efficiency in toughening the resultinglayer composition.

In one embodiment, a three-piece golf ball of the invention comprises acore, an intermediate layer and a cover layer, wherein the core isformed from a rubber composition, the intermediate layer is formed froman ionomeric composition, and the cover is formed from inventivethree-part thermoplastic blend. In one such embodiment, thethermoplastic polymer of the three-part thermoplastic blend is athermoplastic polyurethane composition and each core-shell polymer ofthe plurality is a RayAce®5525 alkyd-acrylic core-shell hybrid. In analternative embodiment, each core-shell polymer of the plurality is oneof RayCore®9534A, RayCore®9507A, RayCore®9506A, and RayCore®9021Aurethane-acrylic core-shell hybrids. In yet another embodiment, theplurality of core-shell polymers include both alkyd-acrylic core-shellhybrids and urethane-acrylic core-shell hybrids. In one embodiment atleast one core of the of the core-shell polymers contain MMA while theshells are urethane. In another embodiment, at least one core of thecore-shell polymers contains urethane while the shell contains MMA. Inyet other embodiments at least one core-shell polymer of the pluralityis non-urethane. The hardness of the resulting layer of in each of theseembodiments may be from about 20 Shore D to about 70 Shore D as long asthe resulting three-part thermoplastic blend has a hardness that isdifferent that a hardness of the thermoplastic polymer of the three-partthermoplastic blend and the modulus of the resulting three-partthermoplastic blend is greater than a modulus of the thermoplasticpolymer of the three-part thermoplastic blend.

In different embodiments, the thermoplastic polymer of the inventivethree-part thermoplastic blend may consist of a thermoplastic polyureacomposition. In alternative embodiments, the thermoplastic polymer ofthe inventive three-part thermoplastic blend may consist of athermoplastic polyurethane-polyurea hybrid composition. In each suchdifferent and alternative embodiments, the inventive three-partthermoplastic blend may include core-shell polymers such as thosesuggested in embodiments wherein the thermoplastic polymer compositionis a polyurethane.

While golf balls of the invention include the inventive three-partthermoplastic blend in an outer cover layer, it is also envisioned thata different golf ball layer (inner core, outer core, intermediate layer,etc.) may alternatively or additionally incorporate the inventivethree-part thermoplastic blend of ionomer, thermoplastic polymer andplurality of core-shell polymers.

In contrast, when a mixture is made that does not include the ionomercomponent, the thermoplastic polymer (thermoplastic polyurethane, athermoplastic urea, a thermoplastic urea-urethane hybrid, orcombinations thereof) and plurality of core-shells and/or polymethylmethacrylate-based copolymer (MMA copolymer) may be included in themixture in a weight ratio of from about 98:2 to about 50:50. In anotherembodiment, the thermoplastic polymer and the MMA copolymer may beincluded in the mixture in a weight ratio of from 95:5 to 55:45. In yetanother embodiment, the thermoplastic polymer and the MMA copolymer maybe included in the mixture in a weight ratio of from 93:7 to 65:35.

Golf balls having various constructions may be made in accordance withthis invention. For example, golf balls having two piece, three piece,four-piece, and five-piece constructions with single or multi-layeredcover materials may be made. Representative illustrations of such golfball constructions are provided and discussed further below. The term,“layer” as used herein means generally any spherical of the golf ball.More particularly, in one version, a two-piece golf ball containing acore surrounded by a cover is made. Three-piece golf balls containing adual-layered core and single-layered cover also can be made. Thedual-core includes an inner core (center) and surrounding outer corelayer. In another version, a four-piece golf ball containing a dual-coreand dual-cover (inner cover and outer cover layers) is made. In yetanother construction, a four-piece or five-piece golf ball containing adual-core; casing layer(s); and cover layer(s) may be made. As usedherein, the term, “casing layer” means a layer of the ball disposedbetween the multi-layered core sub-assembly and cover. The casing layeralso may be referred to as a mantle or intermediate layer. The diameterand thickness of the different layers along with properties such ashardness and compression may vary depending upon the construction anddesired playing performance properties of the golf ball as discussedfurther below.

Thus, golf balls of the invention may have any number of layers,including for example a four piece golf ball wherein the core is a dualcore surrounded by an ionomeric inner cover layer wherein an outer coverlayer of inventive three-part thermoplastic blend is disposed about theinner cover layer. In such embodiments, it is envisioned that the innercore may comprise a thermoset composition or a thermoplastic compositionwhile the outer core layer may be formed from either of a thermosetcomposition or a thermoplastic composition. And the outer cover layer ofinventive three-part thermoplastic blend may consist of numerouspossible variations and combinations of ionomer, thermoplastic polymerselected from thermoplastic polyurethanes, thermoplastic polyureas, andpolyurea-polyurethane hybrids with ASA and/or ABS. Once again, outercover hardnesses may range from 20 shore D to 70 Shore D, although it isenvisioned that the hardness of a layer of inventive three-partthermoplastic blend can be targeted within any known range by modifyingthe ingredients of the ionomer, thermoplastic polymer and selectingparticular ASA and/or ABS, by varying the relative amounts of ionomer,thermoplastic polymer and ASA and/or ABS in the three-part thermoplasticblend, as well as by modifying the processing time and temperature.

In another embodiment, in a four piece golf ball, a rubber-based dualcore may be surrounded by an inner cover layer formed from inventivethree-part thermoplastic blend consisting of ionomer, thermoplasticpolyurea and ASA and/or ABS while an outer cover layer disposedthereabout containing a conventional polyurea composition.

In one embodiment, at least one of the core layers is formed of a rubbercomposition comprising polybutadiene rubber material. More particularly,in one version, the ball contains a single inner core formed of thepolybutadiene rubber composition. In a second version, the ball containsa dual-core comprising an inner core (center) and surrounding outer corelayer.

In one version, the core is formed of a rubber composition comprising arubber material such as, for example, polybutadiene, ethylene-propylenerubber, ethylene-propylene-diene rubber, polyisoprene, styrene-butadienerubber, polyalkenamers, butyl rubber, halobutyl rubber, or polystyreneelastomers. For example, polybutadiene rubber compositions may be usedto form the inner core (center) and surrounding outer core layer in adual-layer construction. In another version, the core may be formed froman ionomer composition comprising an ethylene acid copolymer containingacid groups such that greater than 70% of the acid groups areneutralized. These highly neutralized polymers (HNPs) also may be usedto form at least one core layer in a multi-layered core construction.For example, a polybutadiene rubber composition may be used to form thecenter and a HNP composition may be used to form the outer core. Suchrubber and HNP compositions may be as discussed herein.

In general, polybutadiene is a homopolymer of 1, 3-butadiene. The doublebonds in the 1, 3-butadiene monomer are attacked by catalysts to growthe polymer chain and form a polybutadiene polymer having a desiredmolecular weight. Any suitable catalyst may be used to synthesize thepolybutadiene rubber depending upon the desired properties. Normally, atransition metal complex (for example, neodymium, nickel, or cobalt) oran alkyl metal such as alkyllithium is used as a catalyst. Othercatalysts include, but are not limited to, aluminum, boron, lithium,titanium, and combinations thereof. The catalysts produce polybutadienerubbers having different chemical structures. In a cis-bondconfiguration, the main internal polymer chain of the polybutadieneappears on the same side of the carbon-carbon double bond contained inthe polybutadiene. In a trans-bond configuration, the main internalpolymer chain is on opposite sides of the internal carbon-carbon doublebond in the polybutadiene. The polybutadiene rubber can have variouscombinations of cis- and trans-bond structures. A preferredpolybutadiene rubber has a 1,4 cis-bond content of at least 40%,preferably greater than 80%, and more preferably greater than 90%. Ingeneral, polybutadiene rubbers having a high 1,4 cis-bond content havehigh tensile strength. The polybutadiene rubber may have a relativelyhigh or low Mooney viscosity.

Examples of commercially-available polybutadiene rubbers that can beused in accordance with this invention, include, but are not limited to,BR 01 and BR 1220, available from BST Elastomers of Bangkok, Thailand;SE BR 1220LA and SE BR1203, available from DOW Chemical Co of Midland,Mich.; BUDENE 1207, 1207s, 1208, and 1280 available from Goodyear, Incof Akron, Ohio; BR 01, 51 and 730, available from Japan Synthetic Rubber(JSR) of Tokyo, Japan; BUNA CB 21, CB 22, CB 23, CB 24, CB 25, CB 29MES, CB 60, CB Nd 60, CB 55 NF, CB 70 B, CB KA 8967, and CB 1221,available from Lanxess Corp. of Pittsburgh. Pa.; BR1208, available fromLG Chemical of Seoul, South Korea; UBEPOL BR130B, BR150, BR150B, BR150L,BR230, BR360L, BR710, and VCR617, available from UBE Industries, Ltd. ofTokyo, Japan; EUROPRENE NEOCIS BR 60, INTENE 60 AF and P30AF, andEUROPRENE BR HV80, available from Polimeri Europa of Rome, Italy; AFDENE50 and NEODENE BR40, BR45, BR50 and BR60, available from Karbochem (PTY)Ltd. of Bruma, South Africa; KBR 01, NdBr 40, NdBR-45, NdBr 60, KBR7105, KBR 710H, and KBR 750, available from Kumho Petrochemical Co.,Ltd. Of Seoul, South Korea; and DIENE 55NF, 70AC, and 320 AC, availablefrom Firestone Polymers of Akron, Ohio.

To form the core, the polybutadiene rubber is used in an amount of atleast about 5% by weight based on total weight of composition and isgenerally present in an amount of about 5% to about 100%, or an amountwithin a range having a lower limit of 5% or 10% or 20% or 30% or 40% or50% and an upper limit of 55% or 60% or 70% or 80% or 90% or 95% or100%. In general, the concentration of polybutadiene rubber is about 45to about 95 weight percent. Preferably, the rubber material used to formthe core layer comprises at least 50% by weight, and more preferably atleast 70% by weight, polybutadiene rubber.

The rubber compositions of this invention may be cured, either bypre-blending or post-blending, using conventional curing processes.Suitable curing processes include, for example, peroxide-curing,sulfur-curing, high-energy radiation, and combinations thereof.Preferably, the rubber composition contains a free-radical initiatorselected from organic peroxides, high energy radiation sources capableof generating free-radicals, and combinations thereof. In one preferredversion, the rubber composition is peroxide-cured. Suitable organicperoxides include, but are not limited to, dicumyl peroxide;n-butyl-4,4-di(t-butylperoxy) valerate;1,1-di(t-butylperoxy)3,3,5-trimethylcyclohexane;2,5-dimethyl-2,5-di(t-butylperoxy) hexane; di-t-butyl peroxide;di-t-amyl peroxide; t-butyl peroxide; t-butyl cumyl peroxide;2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3;di(2-t-butyl-peroxyisopropyl)benzene; dilauroyl peroxide; dibenzoylperoxide; t-butyl hydroperoxide; and combinations thereof. In aparticular embodiment, the free radical initiator is dicumyl peroxide,including, but not limited to Perkadox® BC, commercially available fromAkzo Nobel. Peroxide free-radical initiators are generally present inthe rubber composition in an amount of at least 0.05 parts by weight per100 parts of the total rubber, or an amount within the range having alower limit of 0.05 parts or 0.1 parts or 1 part or 1.25 parts or 1.5parts or 2.5 parts or 5 parts by weight per 100 parts of the totalrubbers, and an upper limit of 2.5 parts or 3 parts or 5 parts or 6parts or 10 parts or 15 parts by weight per 100 parts of the totalrubber. Concentrations are in parts per hundred (phr) unless otherwiseindicated. As used herein, the term, “parts per hundred,” also known as“phr” or “pph” is defined as the number of parts by weight of aparticular component present in a mixture, relative to 100 parts byweight of the polymer component. Mathematically, this can be expressedas the weight of an ingredient divided by the total weight of thepolymer, multiplied by a factor of 100.

The rubber compositions preferably include a reactive cross-linkingco-agent. Suitable co-agents include, but are not limited to, metalsalts of unsaturated carboxylic acids having from 3 to 8 carbon atoms;unsaturated vinyl compounds and polyfunctional monomers (e.g.,trimethylolpropane trimethacrylate); phenylene bismaleimide; andcombinations thereof. Particular examples of suitable metal saltsinclude, but are not limited to, one or more metal salts of acrylates,diacrylates, methacrylates, and dimethacrylates, wherein the metal isselected from magnesium, calcium, zinc, aluminum, lithium, and nickel.In a particular embodiment, the co-agent is selected from zinc salts ofacrylates, diacrylates, methacrylates, and dimethacrylates. In anotherparticular embodiment, the agent is zinc diacrylate (ZDA). When theco-agent is zinc diacrylate and/or zinc dimethacrylate, the co-agent istypically included in the rubber composition in an amount within therange having a lower limit of 1 or 5 or 10 or 15 or 19 or 20 parts byweight per 100 parts of the total rubber, and an upper limit of 24 or 25or 30 or 35 or 40 or 45 or 50 or 60 parts by weight per 100 parts of thebase rubber.

Radical scavengers such as a halogenated organosulfur or metal saltthereof, organic disulfide, or inorganic disulfide compounds may beadded to the rubber composition. These compounds also may function as“soft and fast agents.” As used herein, “soft and fast agent” means anycompound or a blend thereof that is capable of making a core: 1) softer(having a lower compression) at a constant “coefficient of restitution”(COR); and/or 2) faster (having a higher COR at equal compression), whencompared to a core equivalently prepared without a soft and fast agent.Preferred halogenated organosulfur compounds include, but are notlimited to, pentachlorothiophenol (PCTP) and salts of PCTP such as zincpentachlorothiophenol (ZnPCTP). Using PCTP and ZnPCTP in golf ball innercores helps produce softer and faster inner cores. The PCTP and ZnPCTPcompounds help increase the resiliency and the coefficient ofrestitution of the core. In a particular embodiment, the soft and fastagent is selected from ZnPCTP, PCTP, ditolyl disulfide, diphenyldisulfide, dixylyl disulfide, 2-nitroresorcinol, and combinationsthereof.

The rubber compositions of the present invention also may include“fillers,” which are added to adjust the density and/or specific gravityof the material. Suitable fillers include, but are not limited to,polymeric or mineral fillers, metal fillers, metal alloy fillers, metaloxide fillers and carbonaceous fillers. The fillers can be in anysuitable form including, but not limited to, flakes, fibers, whiskers,fibrils, plates, particles, and powders. Rubber regrind, which isground, recycled rubber material (for example, ground to about 30 meshparticle size) obtained from discarded rubber golf ball cores, also canbe used as a filler. The amount and type of fillers utilized aregoverned by the amount and weight of other ingredients in the golf ball,since a maximum golf ball weight of 45.93 g (1.62 ounces) has beenestablished by the United States Golf Association (USGA).

Suitable polymeric or mineral fillers that may be added to the rubbercomposition include, for example, precipitated hydrated silica, clay,talc, asbestos, glass fibers, aramid fibers, mica, calcium metasilicate,barium sulfate, zinc sulfide, lithopone, silicates, silicon carbide,tungsten carbide, diatomaceous earth, polyvinyl chloride, carbonatessuch as calcium carbonate and magnesium carbonate. Suitable metalfillers include titanium, tungsten, aluminum, bismuth, nickel,molybdenum, iron, lead, copper, boron, cobalt, beryllium, zinc, and tin.Suitable metal alloys include steel, brass, bronze, boron carbidewhiskers, and tungsten carbide whiskers. Suitable metal oxide fillersinclude zinc oxide, iron oxide, aluminum oxide, titanium oxide,magnesium oxide, and zirconium oxide. Suitable particulate carbonaceousfillers include graphite, carbon black, cotton flock, natural bitumen,cellulose flock, and leather fiber. Micro balloon fillers such as glassand ceramic, and fly ash fillers can also be used. In a particularaspect of this embodiment, the rubber composition includes filler(s)selected from carbon black, nanoclays (e.g., Cloisite® and Nanofil®nanoclays, commercially available from Southern Clay Products, Inc., andNanomax® and Nanomer® nanoclays, commercially available from Nanocor,Inc.), talc (e.g., Luzenac HAR® high aspect ratio talcs, commerciallyavailable from Luzenac America, Inc.), glass (e.g., glass flake, milledglass, and microglass), mica and mica-based pigments (e.g., Iriodin®pearl luster pigments, commercially available from The Merck Group), andcombinations thereof. In a particular embodiment, the rubber compositionis modified with organic fiber micropulp.

In addition, the rubber compositions may include antioxidants to preventthe breakdown of the elastomers. Also, processing aids such as highmolecular weight organic acids and salts thereof, may be added to thecomposition. In a particular embodiment, the total amount of additive(s)and filler(s) present in the rubber composition is 15 wt % or less, or12 wt % or less, or 10 wt % or less, or 9 wt % or less, or 6 wt % orless, or 5 wt % or less, or 4 wt % or less, or 3 wt % or less, based onthe total weight of the rubber composition.

The polybutadiene rubber material (base rubber) may be blended withother elastomers in accordance with this invention. Other elastomersinclude, but are not limited to, polybutadiene, polyisoprene, ethylenepropylene rubber (“EPR”), styrene-butadiene rubber, styrenic blockcopolymer rubbers (such as “SI”, “SIS”, “SB”, “SBS”, “SIBS”, and thelike, where “S” is styrene, “I” is isobutylene, and “B” is butadiene),polyalkenamers such as, for example, polyoctenamer, butyl rubber,halobutyl rubber, polystyrene elastomers, polyethylene elastomers,polyurethane elastomers, polyurea elastomers, metallocene-catalyzedelastomers and plastomers, copolymers of isobutylene and p-alkylstyrene,halogenated copolymers of isobutylene and p-alkylstyrene, copolymers ofbutadiene with acrylonitrile, polychloroprene, alkyl acrylate rubber,chlorinated isoprene rubber, acrylonitrile chlorinated isoprene rubber,and combinations of two or more thereof.

The polymers, free-radical initiators, filler, cross-linking agents, andany other materials used in forming either the golf ball center or anyof the core, in accordance with invention, may be combined to form amixture by any type of mixing known to one of ordinary skill in the art.Suitable types of mixing include single pass and multi-pass mixing, andthe like. The cross-linking agent, and any other optional additives usedto modify the characteristics of the golf ball center or additionallayer(s), may similarly be combined by any type of mixing. A single-passmixing process where ingredients are added sequentially is preferred, asthis type of mixing tends to increase efficiency and reduce costs forthe process. The preferred mixing cycle is single step wherein thepolymer, cis-to-trans catalyst, filler, zinc diacrylate, and peroxideare added in sequence.

In one preferred embodiment, the entire core or at least one core layerin a multi-layered structure is formed of a rubber compositioncomprising a material selected from the group of natural and syntheticrubbers including, but not limited to, polybutadiene, polyisoprene,ethylene propylene rubber (“EPR”), ethylene-propylene-diene (“EPDM”)rubber, styrene-butadiene rubber, styrenic block copolymer rubbers (suchas “SI”, “SIS”, “SB”, “SBS”, “SIBS”, and the like, where “S” is styrene,“I” is isobutylene, and “B” is butadiene), polyalkenamers such as, forexample, polyoctenamer, butyl rubber, halobutyl rubber, polystyreneelastomers, polyethylene elastomers, polyurethane elastomers, polyureaelastomers, metallocene-catalyzed elastomers and plastomers, copolymersof isobutylene and p-alkylstyrene, halogenated copolymers of isobutyleneand p-alkylstyrene, copolymers of butadiene with acrylonitrile,polychloroprene, alkyl acrylate rubber, chlorinated isoprene rubber,acrylonitrile chlorinated isoprene rubber, and combinations of two ormore thereof.

As discussed above, single and multi-layered cores can be made inaccordance with this invention. In two-layered cores, a thermosetmaterial such as, for example, thermoset rubber, can be used to make theouter core layer or a thermoplastic material such as, for example,ethylene acid copolymer containing acid groups that are at leastpartially or fully neutralized can be used to make the outer core layer.Suitable ionomer compositions include partially-neutralized ionomers andhighly-neutralized ionomers (HNPs), including ionomers formed fromblends of two or more partially-neutralized ionomers, blends of two ormore highly-neutralized ionomers, and blends of one or morepartially-neutralized ionomers with one or more highly-neutralizedionomers. Suitable ethylene acid copolymer ionomers and otherthermoplastics that can be used to form the core layer(s) are the samematerials that can be used to make an inner cover layer as discussedfurther below.

In another example, multi-layered cores having an inner core,intermediate core layer, and outer core layer, wherein the intermediatecore layer is disposed between the intermediate and outer core layersmay be prepared in accordance with this invention. More particularly, asdiscussed above, the inner core may be constructed from a thermoplasticor thermoset composition, such as thermoset rubber. Meanwhile, theintermediate and outer core layers also may be formed from thermoset orthermoplastic materials. Suitable thermoset and thermoplasticcompositions that may be used to form the intermediate/outer core layersare discussed above. For example, each of the intermediate and outercore layers may be formed from a thermoset rubber composition. Thus, theintermediate core layer may be formed from a first thermoset rubbercomposition; and the outer core layer may be formed from a secondthermoset rubber composition. In another embodiment, the intermediatecore layer is formed from a thermoset composition; and the outer corelayer is formed from a thermoplastic composition. In a third embodiment,the intermediate core layer is formed from a thermoplastic composition;and the outer core layer is formed from a thermoset composition.Finally, in a fourth embodiment, the intermediate core layer is formedfrom a first thermoplastic composition; and the outer core layer isformed from a second thermoplastic compositions.

Other suitable thermoplastic polymers that may be used to form theintermediate layer include, but are not limited to, the followingpolymers (including homopolymers, copolymers, and derivatives thereof:(a) polyester, particularly those modified with a compatibilizing groupsuch as sulfonate or phosphonate, including modified poly(ethyleneterephthalate), modified poly(butylene terephthalate), modifiedpoly(propylene terephthalate), modified poly(trimethyleneterephthalate), modified poly(ethylene naphthenate), and those disclosedin U.S. Pat. Nos. 6,353,050, 6,274,298, and 6,001,930, the entiredisclosures of which are hereby incorporated herein by reference, andblends of two or more thereof; (b) polyamides, polyamide-ethers, andpolyamide-esters, and those disclosed in U.S. Pat. Nos. 6,187,864,6,001,930, and 5,981,654, the entire disclosures of which are herebyincorporated herein by reference, and blends of two or more thereof; (c)polyurethanes, polyureas, polyurethane-polyurea hybrids, and blends oftwo or more thereof; (d) fluoropolymers, such as those disclosed in U.S.Pat. Nos. 5,691,066, 6,747,110 and 7,009,002, the entire disclosures ofwhich are hereby incorporated herein by reference, and blends of two ormore therof; (e) polystyrenes, such as poly(styrene-co-maleicanhydride), acrylonitrile-butadiene-styrene, poly(styrene sulfonate),polyethylene styrene, and blends of two or more thereof; (f) polyvinylchlorides and grafted polyvinyl chlorides, and blends of two or morethereof; (g) polycarbonates, blends ofpolycarbonate/acrylonitrile-butadiene-styrene, blends ofpolycarbonate/polyurethane, blends of polycarbonate/polyester, andblends of two or more thereof; (h) polyethers, such as polyaryleneethers, polyphenylene oxides, block copolymers of alkenyl aromatics withvinyl aromatics and polyamicesters, and blends of two or more thereof;(i) polyimides, polyetherketones, polyamideimides, and blends of two ormore thereof; and (j) polycarbonate/polyester copolymers and blends.

It also is recognized that thermoplastic materials can be “converted”into thermoset materials by cross-linking the polymer chains so theyform a network structure, and such cross-linked thermoplastic materialsmay be used to form the core and intermediate layers in accordance withthis invention. For example, thermoplastic polyolefins such as linearlow density polyethylene (LLDPE), low density polyethylene (LDPE), andhigh density polyethylene (HDPE) may be cross-linked to form bondsbetween the polymer chains. The cross-linked thermoplastic materialtypically has improved physical properties and strength overnon-cross-linked thermoplastics, particularly at temperatures above thecrystalline melting point. Preferably a partially or fully-neutralizedionomer, as described above, is covalently cross-linked to render itinto a thermoset composition (that is, it contains at least some levelof covalent, irreversable cross-links). Thermoplastic polyurethanes andpolyureas also may be converted into thermoset materials in accordancewith the present invention.

The cross-linked thermoplastic material may be created by exposing thethermoplastic to: 1) a high-energy radiation treatment, such as electronbeam or gamma radiation, such as disclosed in U.S. Pat. No. 5,891,973,which is incorporated by reference herein, 2) lower energy radiation,such as ultra-violet (UV) or infra-red (IR) radiation; 3) a solutiontreatment, such as an isocyanate or a silane; 4) incorporation ofadditional free radical initiator groups in the thermoplastic prior tomolding; and/or 5) chemical modification, such as esterification orsaponification, to name a few.

Modifications in thermoplastic polymeric structure can be induced by anumber of methods, including exposing the thermoplastic material tohigh-energy radiation or through a chemical process using peroxide.Radiation sources include, but are not limited to, gamma-rays,electrons, neutrons, protons, x-rays, helium nuclei, or the like. Gammaradiation, typically using radioactive cobalt atoms and allows forconsiderable depth of treatment, if necessary. For core layers requiringlower depth of penetration, electron-beam accelerators or UV and IRlight sources can be used. Useful UV and IR irradiation methods aredisclosed in U.S. Pat. Nos. 6,855,070 and 7,198,576, which areincorporated herein by reference. The thermoplastic layers may beirradiated at dosages greater than 0.05 Mrd, or ranging from 1 Mrd to 20Mrd, or ranging from 2 Mrd to 15 Mrd, or ranging from 4 Mrd to 10 Mrd.In one embodiment, the layer may be irradiated at a dosage from 5 Mrd to8 Mrd and in another embodiment, the layer may be irradiated with adosage from 0.05 Mrd to 3 Mrd, or from 0.05 Mrd to 1.5 Mrd.

The solid cores for the golf balls of this invention may be made usingany suitable conventional technique such as, for example, compression orinjection-molding, Typically, the cores are formed by compressionmolding a slug of uncured or lightly cured rubber material into aspherical structure. Prior to forming the cover layer, the corestructure may be surface-treated to increase the adhesion between itsouter surface and adjacent layer. Such surface-treatment may includemechanically or chemically-abrading the outer surface of the core. Forexample, the core may be subjected to corona-discharge,plasma-treatment, silane-dipping, or other treatment methods known tothose in the art. The cover layers are formed over the core or ballsub-assembly (the core structure and any intermediate layers disposedabout the core) using any suitable method as described further below.Prior to forming the cover layers, the ball sub-assembly may besurface-treated to increase the adhesion between its outer surface andthe overlying cover material using the above-described techniques.

Conventional compression and injection-molding and other methods can beused to form cover layers over the core or ball sub-assembly. Ingeneral, compression molding normally involves first making half(hemispherical) shells by injection-molding the composition in aninjection mold. This produces semi-cured, semi-rigid half-shells (orcups). Then, the half-shells are positioned in a compression mold aroundthe core or ball sub-assembly. Heat and pressure are applied and thehalf-shells fuse together to form a cover layer over the core orsub-assembly. Compression molding also can be used to cure the covercomposition after injection-molding. For example, a thermally-curablecomposition can be injection-molded around a core in an unheated mold.After the composition is partially hardened, the ball is removed andplaced in a compression mold. Heat and pressure are applied to the balland this causes thermal-curing of the outer cover layer.

Retractable pin injection-molding (RPIM) methods generally involve usingupper and lower mold cavities that are mated together. The upper andlower mold cavities form a spherical interior cavity when they arejoined together. The mold cavities used to form the outer cover layerhave interior dimple cavity details. The cover material conforms to theinterior geometry of the mold cavities to form a dimple pattern on thesurface of the ball. The injection-mold includes retractable supportpins positioned throughout the mold cavities. The retractable supportpins move in and out of the cavity. The support pins help maintain theposition of the core or ball sub-assembly while the molten compositionflows through the mold gates. The molten composition flows into thecavity between the core and mold cavities to surround the core and formthe cover layer. Other methods can be used to make the cover including,for example, reaction injection-molding (RIM), liquid injection-molding,casting, spraying, powder-coating, vacuum-forming, flow-coating,dipping, spin-coating, and the like.

As discussed above, an inner cover layer or intermediate layer,preferably formed from an ethylene acid copolymer ionomer composition,can be formed between the core or ball sub-assembly and cover layer. Theintermediate layer comprising the ionomer composition may be formedusing a conventional technique such as, for example, compression orinjection-molding. For example, the ionomer composition may beinjection-molded or placed in a compression mold to produce half-shells.These shells are placed around the core in a compression mold, and theshells fuse together to form an intermediate layer. Alternatively, theionomer composition is injection-molded directly onto the core usingretractable pin injection-molding.

After the golf balls have been removed from the mold, they may besubjected to finishing steps such as flash-trimming, surface-treatment,marking, and one or more coating layer may be applied as desired viamethods such as spraying, dipping, brushing, or rolling. Then the golfball can go through a series of finishing steps.

For example, in traditional white-colored golf balls, thewhite-pigmented outer cover layer may be surface-treated using asuitable method such as, for example, corona, plasma, or ultraviolet(UV) light-treatment. In another finishing process, the golf balls arepainted with one or more paint coatings. For example, white or clearprimer paint may be applied first to the surface of the ball and thenindicia may be applied over the primer followed by application of aclear polyurethane top-coat. Indicia such as trademarks, symbols, logos,letters, and the like may be printed on the outer cover or prime-coatedlayer, or top-coated layer using pad-printing, ink-jet printing,dye-sublimation, or other suitable printing methods. Any of the surfacecoatings may contain a fluorescent optical brightener.

The golf balls of this invention provide the ball with a variety ofadvantageous mechanical and playing performance properties as discussedfurther below. In general, the hardness, diameter, and thickness of thedifferent ball layers may vary depending upon the desired ballconstruction. Thus, golf balls of the invention may have any knownoverall diameter and any known number of different layers and layerthicknesses, wherein the inventive three-part thermoplastic blend isincorporated in one or more of those layers in order to target desiredplaying characteristics.

For example, the core may have a diameter ranging from about 0.09 inchesto about 1.65 inches. In one embodiment, the diameter of the core of thepresent invention is about 1.2 inches to about 1.630 inches. When partof a two-piece ball according to invention, the core may have a diameterranging from about 1.5 inches to about 1.62 inches. In anotherembodiment, the diameter of the core is about 1.3 inches to about 1.6inches, preferably from about 1.39 inches to about 1.6 inches, and morepreferably from about 1.5 inches to about 1.6 inches. In yet anotherembodiment, the core has a diameter of about 1.55 inches to about 1.65inches, preferably about 1.55 inches to about 1.60 inches.

In some embodiments, the core may have an overall diameter within arange having a lower limit of 0.500 or 0.700 or 0.750 or 0.800 or 0.850or 0.900 or 0.950 or 1.000 or 1.100 or 1.150 or 1.200 or 1.250 or 1.300or 1.350 or 1.400 or 1.450 or 1.500 or 1.600 or 1.610 inches and anupper limit of 1.620 or 1.630 or 1.640 inches. In a particularembodiment, the core is a multi-layer core having an overall diameterwithin a range having a lower limit of 0.500 or 0.700 or 0.750 or 0.800or 0.850 or 0.900 or 0.950 or 1.000 or 1.100 or 1.150 or 1.200 inchesand an upper limit of 1.250 or 1.300 or 1.350 or 1.400 or 1.450 or 1.500or 1.600 or 1.610 or 1.620 or 1.630 or 1.640 inches. In anotherparticular embodiment, the multi-layer core has an overall diameterwithin a range having a lower limit of 0.500 or 0.700 or 0.750 inchesand an upper limit of 0.800 or 0.850 or 0.900 or 0.950 or 1.000 or 1.100or 1.150 or 1.200 or 1.250 or 1.300 or 1.350 or 1.400 or 1.450 or 1.500or 1.600 or 1.610 or 1.620 or 1.630 or 1.640 inches. In anotherparticular embodiment, the multi-layer core has an overall diameter of1.500 inches or 1.510 inches or 1.530 inches or 1.550 inches or 1.570inches or 1.580 inches or 1.590 inches or 1.600 inches or 1.610 inchesor 1.620 inches.

In some embodiments, the inner core can have an overall diameter of0.500 inches or greater, or 0.700 inches or greater, or 1.00 inches orgreater, or 1.250 inches or greater, or 1.350 inches or greater, or1.390 inches or greater, or 1.450 inches or greater, or an overalldiameter within a range having a lower limit of 0.250 or 0.500 or 0.750or 1.000 or 1.250 or 1.350 or 1.390 or 1.400 or 1.440 inches and anupper limit of 1.460 or 1.490 or 1.500 or 1.550 or 1.580 or 1.600inches, or an overall diameter within a range having a lower limit of0.250 or 0.300 or 0.350 or 0.400 or 0.500 or 0.550 or 0.600 or 0.650 or0.700 inches and an upper limit of 0.750 or 0.800 or 0.900 or 0.950 or1.000 or 1.100 or 1.150 or 1.200 or 1.250 or 1.300 or 1.350 or 1.400inches.

In some embodiments, the outer core layer can have an overall thicknesswithin a range having a lower limit of 0.010 or 0.020 or 0.025 or 0.030or 0.035 inches and an upper limit of 0.040 or 0.070 or 0.075 or 0.080or 0.100 or 0.150 inches, or an overall thickness within a range havinga lower limit of 0.025 or 0.050 or 0.100 or 0.150 or 0.160 or 0.170 or0.200 inches and an upper limit of 0.225 or 0.250 or 0.275 or 0.300 or0.325 or 0.350 or 0.400 or 0.450 or greater than 0.450 inches. The outercore layer may alternatively have a thickness of greater than 0.10inches, or 0.20 inches or greater, or greater than 0.20 inches, or 0.30inches or greater, or greater than 0.30 inches, or 0.35 inches orgreater, or greater than 0.35 inches, or 0.40 inches or greater, orgreater than 0.40 inches, or 0.45 inches or greater, or greater than0.45 inches, or a thickness within a range having a lower limit of 0.005or 0.010 or 0.015 or 0.020 or 0.025 or 0.030 or 0.035 or 0.040 or 0.045or 0.050 or 0.055 or 0.060 or 0.065 or 0.070 or 0.075 or 0.080 or 0.090or 0.100 or 0.200 or 0.250 inches and an upper limit of 0.300 or 0.350or 0.400 or 0.450 or 0.500 or 0.750 inches.

An intermediate core layer can have any known overall thickness such aswithin a range having a lower limit of 0.005 or 0.010 or 0.015 or 0.020or 0.025 or 0.030 or 0.035 or 0.040 or 0.045 inches and an upper limitof 0.050 or 0.055 or 0.060 or 0.065 or 0.070 or 0.075 or 0.080 or 0.090or 0.100 inches.

The cores and core layers of golf balls of the invention may havevarying hardnesses depending on the particular golf ball constructionand playing characteristics being targeted. Core center and/or layerhardness can range, for example, from 35 Shore C to about 98 Shore C, or50 Shore C to about 90 Shore C, or 60 Shore C to about 85 Shore C, or 45Shore C to about 75 Shore C, or 40 Shore C to about 85 Shore C. In otherembodiments, core center and/or layer hardness can range, for example,from about 20 Shore D to about 78 Shore D, or from about 30 Shore D toabout 60 Shore D, or from about 40 Shore D to about 50 Shore D, or 50Shore D or less, or greater than 50 Shore D.

The compression of the core is generally overall in the range of about40 to about 110, although embodiments are envisioned wherein thecompression of the core is as low as 5. In other embodiments, theoverall CoR of cores of the present invention at 125 ft/s is at least0.750, or at least 0.775 or at least 0.780, or at least 0.785, or atleast 0.790, or at least 0.795, or at least 0.800. Cores are also knownto comprise rubbers and also may be formed of a variety of othermaterials that are typically also used for intermediate and coverlayers. Intermediate layers may likewise also comprise materialsgenerally used in cores and covers as described herein for example.

An intermediate layer is sometimes thought of as including any layer(s)disposed between the inner core (or center) and the outer cover of agolf ball, and thus in some embodiments, the intermediate layer mayinclude an outer core layer, a casing layer, or inner cover layer(s). Inthis regard, a golf ball of the invention may include one or moreintermediate layers. An intermediate layer may be used, if desired, witha multilayer cover or a multilayer core, or with both a multilayer coverand a multilayer core.

In one non-limiting embodiment, an intermediate layer having a thicknessof about 0.010 inches to about 0.06 inches, is disposed about a corehaving a diameter ranging from about 1.5 inches to about 1.59 inches.

Intermediate layer(s) may be formed, at least in part, from one or morehomopolymeric or copolymeric materials, such as ionomers, primarily orfully non-ionomeric thermoplastic materials, vinyl resins, polyolefins,polyurethanes, polyureas, polyamides, acrylic resins and blends thereof,olefinic thermoplastic rubbers, block copolymers of styrene andbutadiene, isoprene or ethylene-butylene rubber, copoly(ether-amide),polyphenylene oxide resins or blends thereof, and thermoplasticpolyesters. However, embodiments are envisioned wherein at least oneintermediate layer is formed from a different material commonly used ina core and/or cover layer.

The range of thicknesses for an intermediate layer of a golf ball islarge because of the vast possibilities when using an intermediatelayer, i.e., as an outer core layer, an inner cover layer, a woundlayer, a moisture/vapor barrier layer. When used in a golf ball of thepresent invention, the intermediate layer, or inner cover layer, mayhave a thickness about 0.3 inches or less. In one embodiment, thethickness of the intermediate layer is from about 0.002 inches to about0.1 inches, and preferably about 0.01 inches or greater. For example,when part of a three-piece ball or multi-layer ball according to theinvention, the intermediate layer and/or inner cover layer may have athickness ranging from about 0.010 inches to about 0.06 inches. Inanother embodiment, the intermediate layer thickness is about 0.05inches or less, or about 0.01 inches to about 0.045 inches for example.

If the ball includes an intermediate layer or inner cover layer, thehardness (material) may for example be about 50 Shore D or greater, morepreferably about 55 Shore D or greater, and most preferably about 60Shore D or greater. In one embodiment, the inner cover has a Shore Dhardness of about 62 to about 90 Shore D. In one example, the innercover has a hardness of about 68 Shore D or greater. In addition, thethickness of the inner cover layer is preferably about 0.015 inches toabout 0.100 inches, more preferably about 0.020 inches to about 0.080inches, and most preferably about 0.030 inches to about 0.050 inches,but once again, may be changed to target playing characteristics.

The cover typically has a thickness to provide sufficient strength, goodperformance characteristics, and durability. In one embodiment, thecover thickness may for example be from about 0.02 inches to about 0.12inches, or about 0.1 inches or less. For example, the cover may be partof a two-piece golf ball and have a thickness ranging from about 0.03inches to about 0.09 inches. In another embodiment, the cover thicknessmay be about 0.05 inches or less, or from about 0.02 inches to about0.05 inches, or from about 0.02 inches and about 0.045 inches. The covermay be a single-, dual-, or multi-layer cover and have an overallthickness for example within a range having a lower limit of 0.010 or0.020 or 0.025 or 0.030 or 0.040 or 0.045 inches and an upper limit of0.050 or 0.060 or 0.070 or 0.075 or 0.080 or 0.090 or 0.100 or 0.150 or0.200 or 0.300 or 0.500 inches. In a particular embodiment, the covermay be a single layer having a thickness of from 0.010 or 0.020 or 0.025inches to 0.035 or 0.040 or 0.050 inches. In another particularembodiment, the cover may consist of an inner cover layer having athickness of from 0.010 or 0.020 or 0.025 inches to 0.035 or 0.050inches and an outer cover layer having a thickness of from 0.010 or0.020 or 0.025 inches to 0.035 or 0.040 inches.

The outer cover preferably has a thickness within a range having a lowerlimit of about 0.004 or 0.010 or 0.020 or 0.030 or 0.040 inches and anupper limit of about 0.050 or 0.055 or 0.065 or 0.070 or 0.080 inches.Preferably, the thickness of the outer cover is about 0.020 inches orless. The outer cover preferably has a surface hardness of 75 Shore D orless, 65 Shore D or less, or 55 Shore D or less, or 50 Shore D or less,or 50 Shore D or less, or 45 Shore D or less. Preferably, the outercover has hardness in the range of about 20 to about 70 Shore D. In oneexample, the outer cover has hardness in the range of about 25 to about65 Shore D. In one embodiment, the cover may be a single layer having asurface hardness for example of 60 Shore D or greater, or 65 Shore D orgreater. In a particular aspect of this embodiment, the cover is formedfrom a composition having a material hardness of 60 Shore D or greater,or 65 Shore D or greater.

In another particular embodiment, the cover may be a single layer havinga thickness of from 0.010 or 0.020 inches to 0.035 or 0.050 inches andformed from a composition having a material hardness of from 60 or 62 or65 Shore D to 65 or 70 or 72 Shore D.

In yet another particular embodiment, the cover is a single layer havinga thickness of from 0.010 or 0.025 inches to 0.035 or 0.040 inches andformed from a composition having a material hardness of 62 Shore D orless, or less than 62 Shore D, or 60 Shore D or less, or less than 60Shore D, or 55 Shore D or less, or less than 55 Shore D.

In still another particular embodiment, the cover is a single layerhaving a thickness of from 0.010 or 0.025 inches to 0.035 or 0.040inches and formed from a composition having a material hardness of 62Shore D or less, or less than 62 Shore D, or 60 Shore D or less, or lessthan 60 Shore D, or 55 Shore D or less, or less than 55 Shore D.

In an alternative embodiment, the cover may comprise an inner coverlayer and an outer cover layer. The inner cover layer composition mayhave a material hardness of from 60 or 62 or 65 Shore D to 65 or 70 or72 Shore D. The inner cover layer may have a thickness within a rangehaving a lower limit of 0.010 or 0.020 or 0.030 inches and an upperlimit of 0.035 or 0.040 or 0.050 inches. The outer cover layercomposition may have a material hardness of 62 Shore D or less, or lessthan 62 Shore D, or 60 Shore D or less, or less than 60 Shore D, or 55Shore D or less, or less than 55 Shore D. The outer cover layer may havea thickness within a range having a lower limit of 0.010 or 0.020 or0.025 inches and an upper limit of 0.035 or 0.040 or 0.050 inches.

In yet another embodiment, the cover is a dual- or multi-layer coverincluding an inner or intermediate cover layer and an outer cover layer.The inner cover layer may have a surface hardness of 70 Shore D or less,or 65 Shore D or less, or less than 65 Shore D, or a Shore D hardness offrom 50 to 65, or a Shore D hardness of from 57 to 60, or a Shore Dhardness of 58, and a thickness within a range having a lower limit of0.010 or 0.020 or 0.030 inches and an upper limit of 0.045 or 0.080 or0.120 inches. The outer cover layer may have a material hardness of 65Shore D or less, or 55 Shore D or less, or 45 Shore D or less, or 40Shore D or less, or from 25 Shore D to 40 Shore D, or from 30 Shore D to40 Shore D. The outer cover layer may have a surface hardness within arange having a lower limit of 20 or 30 or 35 or 40 Shore D and an upperlimit of 52 or 58 or 60 or 65 or 70 or 72 or 75 Shore D. The outer coverlayer may have a thickness within a range having a lower limit of 0.010or 0.015 or 0.025 inches and an upper limit of 0.035 or 0.040 or 0.045or 0.050 or 0.055 or 0.075 or 0.080 or 0.115 inches.

All this being said, embodiments are also envisioned wherein one or moreof the cover layers is formed from a material typically incorporated ina core or intermediate layer.

It is envisioned that golf balls of the invention may also incorporateconventional coating layer(s) for the purposes usually incorporated. Forexample, one or more coating layer may have a combined thickness of fromabout 0.1 μm to about 100 μm, or from about 2 μm to about 50 μm, or fromabout 2 μm to about 30 μm. Meanwhile, each coating layer may have athickness of from about 0.1 μm to about 50 μm, or from about 0.1 μm toabout 25 μm, or from about 0.1 μm to about 14 μm, or from about 2 μm toabout 9 μm, for example.

It is envisioned that layers a golf ball of the invention may beincorporated via any of casting, compression molding, injection molding,or thermoforming.

The resulting balls of this invention have good impact durability andcut/shear-resistance. The United States Golf Association (“USGA”) hasset total weight limits for golf balls. Particularly, the USGA hasestablished a maximum weight of 45.93 g (1.62 ounces) for golf balls.There is no lower weight limit. In addition, the USGA requires that golfballs used in competition have a diameter of at least 1.68 inches. Thereis no upper limit so many golf balls have an overall diameter fallingwithin the range of about 1.68 to about 1.80 inches. The golf balldiameter is preferably about 1.68 to 1.74 inches, more preferably about1.68 to 1.70 inches. In accordance with the present invention, theweight, diameter, and thickness of the core and cover layers may beadjusted, as needed, so the ball meets USGA specifications of a maximumweight of 1.62 ounces and a minimum diameter of at least 1.68 inches.

Preferably, the golf ball has a Coefficient of Restitution (CoR) of atleast 0.750 and more preferably at least 0.800 (as measured per the testmethods below). The core of the golf ball generally has a compression inthe range of about 30 to about 130 and more preferably in the range ofabout 70 to about 110 (as measured per the test methods below.) Theseproperties allow players to generate greater ball velocity off the teeand achieve greater distance with their drives. At the same time, therelatively thin outer cover layer means that a player will have a morecomfortable and natural feeling when striking the ball with a club. Theball is more playable and its flight path can be controlled more easily.This control allows the player to make better approach shots near thegreen. Furthermore, the outer covers of this invention have good impactdurability and mechanical strength.

The following test methods may be used to obtain certain properties inconnection with the inventive three-part thermoplastic blend of theinvention as well as other materials that may be incorporated in golfballs of the invention.

Hardness.

The center hardness of a core is obtained according to the followingprocedure. The core is gently pressed into a hemispherical holder havingan internal diameter approximately slightly smaller than the diameter ofthe core, such that the core is held in place in the hemispherical ofthe holder while concurrently leaving the geometric central plane of thecore exposed. The core is secured in the holder by friction, such thatit will not move during the cutting and grinding steps, but the frictionis not so excessive that distortion of the natural shape of the corewould result. The core is secured such that the parting line of the coreis roughly parallel to the top of the holder. The diameter of the coreis measured 90 degrees to this orientation prior to securing. Ameasurement is also made from the bottom of the holder to the top of thecore to provide a reference point for future calculations. A rough cutis made slightly above the exposed geometric center of the core using aband saw or other appropriate cutting tool, making sure that the coredoes not move in the holder during this step. The remainder of the core,still in the holder, is secured to the base plate of a surface grindingmachine. The exposed ‘rough’ surface is ground to a smooth, flatsurface, revealing the geometric center of the core, which can beverified by measuring the height from the bottom of the holder to theexposed surface of the core, making sure that exactly half of theoriginal height of the core, as measured above, has been removed towithin 0.004 inches. Leaving the core in the holder, the center of thecore is found with a center square and carefully marked and the hardnessis measured at the center mark according to ASTM D-2240. Additionalhardness measurements at any distance from the center of the core canthen be made by drawing a line radially outward from the center mark,and measuring the hardness at any given distance along the line,typically in 2 mm increments from the center. The hardness at aparticular distance from the center should be measured along at leasttwo, preferably four, radial arms located 180° apart, or 90° apart,respectively, and then averaged. All hardness measurements performed ona plane passing through the geometric center are performed while thecore is still in the holder and without having disturbed itsorientation, such that the test surface is constantly parallel to thebottom of the holder, and thus also parallel to the properly alignedfoot of the durometer.

The outer surface hardness of a golf ball layer is measured on theactual outer surface of the layer and is obtained from the average of anumber of measurements taken from opposing hemispheres, taking care toavoid making measurements on the parting line of the core or on surfacedefects, such as holes or protrusions. Hardness measurements are madepursuant to ASTM D-2240 “Indentation Hardness of Rubber and Plastic byMeans of a Durometer.” Because of the curved surface, care must be takento ensure that the golf ball or golf ball sub-assembly is centered underthe durometer indenter before a surface hardness reading is obtained. Acalibrated, digital durometer, capable of reading to 0.1 hardness unitsis used for the hardness measurements. The digital durometer must beattached to, and its foot made parallel to, the base of an automaticstand. The weight on the durometer and attack rate conforms to ASTMD-2240.

In certain embodiments, a point or plurality of points measured alongthe “positive” or “negative” gradients may be above or below a line fitthrough the gradient and its outermost and innermost hardness values. Inan alternative preferred embodiment, the hardest point along aparticular steep “positive” or “negative” gradient may be higher thanthe value at the innermost of the inner core (the geometric center) orouter core layer (the inner surface)—as long as the outermost point(i.e., the outer surface of the inner core) is greater than (for“positive”) or lower than (for “negative”) the innermost point (i.e.,the geometric center of the inner core or the inner surface of the outercore layer), such that the “positive” and “negative” gradients remainintact.

As discussed above, the direction of the hardness gradient of a golfball layer is defined by the difference in hardness measurements takenat the outer and inner surfaces of a particular layer. The centerhardness of an inner core and hardness of the outer surface of an innercore in a single-core ball or outer core layer are readily determinedaccording to the test procedures provided above. The outer surface ofthe inner core layer (or other optional intermediate core layers) in adual-core ball are also readily determined according to the proceduresgiven herein for measuring the outer surface hardness of a golf balllayer, if the measurement is made prior to surrounding the layer with anadditional core layer. Once an additional core layer surrounds a layerof interest, the hardness of the inner and outer surfaces of any inneror intermediate layers can be difficult to determine. Therefore, forpurposes of the present invention, when the hardness of the inner orouter surface of a core layer is needed after the inner layer has beensurrounded with another core layer, the test procedure described abovefor measuring a point located 1 mm from an interface is used.

Also, it should be understood that there is a fundamental differencebetween “material hardness” and “hardness as measured directly on a golfball.” For purposes of the present invention, material hardness ismeasured according to ASTM D2240 and generally involves measuring thehardness of a flat “slab” or “button” formed of the material. Surfacehardness as measured directly on a golf ball (or other sphericalsurface) typically results in a different hardness value. The differencein “surface hardness” and “material hardness” values is due to severalfactors including, but not limited to, ball construction (that is, coretype, number of cores and/or cover layers, and the like); ball (orsphere) diameter; and the material composition of adjacent layers. Italso should be understood that the two measurement techniques are notlinearly related and, therefore, one hardness value cannot easily becorrelated to the other. Shore hardness (for example, Shore C or Shore Dor Shore A hardness) was measured according to the test method ASTMD-2240.

Modulus.

As used herein, “modulus” or “flexural modulus” refers to flexuralmodulus as measured using a standard flex bar according to ASTM D790-B.

Tensile Strength.

As used herein, tensile strength refers to tensile strength as measuredusing ASTM D-638.

Ultimate Elongation.

As used herein, ultimate elongation refers to ultimate elongation asmeasured using ASTM D-638.

Compression.

As disclosed in Jeff Dalton's Compression by Any Other Name, Science andGolf IV, Proceedings of the World Scientific Congress of Golf (EricThain ed., Routledge, 2002) (“J. Dalton”), several different methods canbe used to measure compression, including Atti compression, Riehlecompression, load/deflection measurements at a variety of fixed loadsand offsets, and effective modulus. For purposes of the presentinvention, compression refers to Soft Center Deflection Index (“SCDI”).The SCDI is a program change for the Dynamic Compression Machine (“DCM”)that allows determination of the pounds required to deflect a core 10%of its diameter. The DCM is an apparatus that applies a load to a coreor ball and measures the number of inches the core or ball is deflectedat measured loads. A crude load/deflection curve is generated that isfit to the Atti compression scale that results in a number beinggenerated that represents an Atti compression. The DCM does this via aload cell attached to the bottom of a hydraulic cylinder that istriggered pneumatically at a fixed rate (typically about 1.0 ft/s)towards a stationary core. Attached to the cylinder is an LVDT thatmeasures the distance the cylinder travels during the testing timeframe.A software-based logarithmic algorithm ensures that measurements are nottaken until at least five successive increases in load are detectedduring the initial phase of the test. The SCDI is a slight variation ofthis set up. The hardware is the same, but the software and output haschanged. With the SCDI, the interest is in the pounds of force requiredto deflect a core x amount of inches. That amount of deflection is 10%percent of the core diameter. The DCM is triggered, the cylinderdeflects the core by 10% of its diameter, and the DCM reports back thepounds of force required (as measured from the attached load cell) todeflect the core by that amount. The value displayed is a single numberin units of pounds.

Coefficient of Restitution (“CoR”).

The CoR is determined according to a known procedure, wherein a golfball or golf ball sub-assembly (for example, a golf ball core) is firedfrom an air cannon at two given velocities and a velocity of 125 ft/s isused for the calculations. Ballistic light screens are located betweenthe air cannon and steel plate at a fixed distance to measure ballvelocity. As the ball travels toward the steel plate, it activates eachlight screen and the ball's time period at each light screen ismeasured. This provides an incoming transit time period which isinversely proportional to the ball's incoming velocity. The ball makesimpact with the steel plate and rebounds so it passes again through thelight screens. As the rebounding ball activates each light screen, theball's time period at each screen is measured. This provides an outgoingtransit time period which is inversely proportional to the ball'soutgoing velocity. The CoR is then calculated as the ratio of the ball'soutgoing transit time period to the ball's incoming transit time period(CoR=V_(out)/V_(in)=T_(out)).

Thermoset and thermoplastic layers herein may be treated in such amanner as to create a positive or negative hardness gradient within andbetween golf ball layers. In golf ball layers of the present inventionwherein a thermosetting rubber is used, gradient-producing processesand/or gradient-producing rubber formulation may be employed.Gradient-producing processes and formulations are disclosed more fully,for example, in U.S. patent application Ser. No. 12/048,665, filed onMar. 14, 2008; Ser. No. 11/829,461, filed on Jul. 27, 2007; Ser. No.11/772,903, filed Jul. 3, 2007; Ser. No. 11/832,163, filed Aug. 1, 2007;Ser. No. 11/832,197, filed on Aug. 1, 2007; the entire disclosure ofeach of these references is hereby incorporated herein by reference.

It is understood that the golf balls of the invention, incorporating atleast one layer of inventive three-part thermoplastic blend, asdescribed and illustrated herein represent only some of the manyembodiments of the invention. It is appreciated by those skilled in theart that various changes and additions can be made to such golf ballswithout departing from the spirit and scope of this invention. It isintended that all such embodiments be covered by the appended claims.

A golf ball of the invention may further incorporate indicia, which asused herein, is considered to mean any symbol, letter, group of letters,design, or the like, that can be added to the dimpled surface of a golfball.

Golf balls of the present invention will typically have dimple coverageof 60% or greater, preferably 65% or greater, and more preferably 75% orgreater. It will be appreciated that any known dimple pattern may beused with any number of dimples having any shape or size. For example,the number of dimples may be 252 to 456, or 330 to 392 and may compriseany width, depth, and edge angle. The parting line configuration of saidpattern may be either a straight line or a staggered wave parting line(SWPL), for example.

In any of these embodiments the single-layer core may be replaced with atwo or more layer core wherein at least one core layer has a hardnessgradient.

Other than in the operating examples, or unless otherwise expresslyspecified, all of the numerical ranges, amounts, values and percentagessuch as those for amounts of materials and others in the specificationmay be read as if prefaced by the word “about” even though the term“about” may not expressly appear with the value, amount or range.Accordingly, unless indicated to the contrary, the numerical parametersset forth in the specification and attached claims are approximationsthat may vary depending upon the desired properties sought to beobtained by the present invention. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical parameter should at least beconstrued in light of the number of reported significant digits and byapplying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contain certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements. Furthermore, when numerical ranges ofvarying scope are set forth herein, it is contemplated that anycombination of these values inclusive of the recited values may be used.

Although the golf ball of the invention has been described herein withreference to particular means and materials, it is to be understood thatthe invention is not limited to the particulars disclosed and extends toall equivalents within the scope of the claims.

It is understood that the manufacturing methods, compositions,constructions, and products described and illustrated herein representonly some embodiments of the invention. It is appreciated by thoseskilled in the art that various changes and additions can be made tocompositions, constructions, and products without departing from thespirit and scope of this invention. It is intended that all suchembodiments be covered by the appended claims.

What is claimed is:
 1. A golf ball comprising at least one layer comprising a thermoplastic blend of: (i) at least one ionomer; (ii) at least one thermoplastic polyurethane; and (iii) at least one acrylonitrile styrene acrylate, acrylonitrile butadiene styrene, or combinations thereof (“ASA and/or ABS”); wherein the ionomer is present in an amount of about 45 wt % or greater and the ASA and/or ABS is present in an amount of from about 2 wt % to about 35 wt %.
 2. The golf ball of claim 1, wherein the thermoplastic polyurethane is present in an amount of from about 8 wt % to about 50 wt %.
 3. The golf ball of claim 2, wherein the thermoplastic polyurethane is present in an amount of from about 25 wt % to about 45 wt %.
 4. The golf ball of claim 3, wherein the thermoplastic polyurethane is present in an amount of from about 35 wt % to about 50 wt %.
 5. The golf ball of claim 2, wherein the ionomer is present in an amount greater than the amount of thermoplastic polyurethane.
 6. The golf ball of claim 1, wherein the ionomer is present in an amount of from about 45 wt % to about 70 wt %.
 7. The golf ball of claim 1, wherein the thermoplastic polyurethane is present in an amount greater than 20 wt % and up to about 40 wt %; and the ASA and/or ABS is present in an amount of from about 5 wt % to about 30 wt %.
 8. The golf ball of claim 1, wherein the ASA is comprised of at least 60% acrylate and/or the ABS is comprised of at least 60% butadiene.
 9. The golf ball of claim 1, wherein the thermoplastic polymer has a material hardness of from about 20 Shore D to about 65 Shore D.
 10. The golf ball of claim 1, wherein the thermoplastic blend has a material hardness that is different than the material hardness of the thermoplastic polymer.
 11. The golf ball of claim 1, wherein the thermoplastic blend has a material hardness greater than about 20 Shore D and up to about 70 Shore D.
 12. The golf ball of claim 1, wherein the at least one layer is a cover layer that surrounds a subassembly and has a hardness H that differs from a hardness H_((ii)) of (ii) by at least about 5 Shore D hardness points; wherein (ii) has a hardness of from about 20 Shore D to about 70 Shore D.
 13. The golf ball of claim 1, wherein the at least one layer is an inner cover layer that surrounds a subassembly and is surrounded by an outer cover layer and has a hardness H that differs from a hardness H_((ii)) of (ii) by at least about 5 Shore D hardness points; wherein (ii) has a hardness of from about 20 Shore D to about 70 Shore D.
 14. The golf ball of claim 1, wherein the at least one layer consists of the thermoplastic blend. 